2015-05-28

The battle for the living room (i.e, controlling the television experience) is heating up with forays from multiple vendors. As the cord-cutting trend gains momentum, the time seems to be right for disruption. Roku has been around for a long time and they continue to taste success with inexpensive and small over-the-top set-top boxes (OTT STBs). At the other end of the spectrum is the Apple TV, which, despite just being a 'hobby', has managed to move millions of units. Google had tried to make inroads into this market a few years back with the Google TV / Logitech Revue, but, it unfortunately didn't pan out as expected. Chromecast turned out to be more popular in their second attempt, but it was a limited play. In late 2014, Google launched Android TV along with the Nexus Player.

Coinciding with Google I/O, NVIDIA is releasing their previously announced SHIELD Android TV. First announed back in March at the 2015 Game Developers Conference, SHIELD Android TV is a premium 4K-capable over-the-top set-top box (OTT STB) with a powerful graphics engine. The differentiating aspects compared to the Intel Bay Trail-based Nexus Player and the Qualcomm Snapdragon-based Razer Forge TV lie in 4K support (HDMI 2.0 / HDCP 2.2 / Netflix 4K-certification) and excellent gaming credentials.

NVIDIA SHIELD Family

NVIDIA SHIELD Tablet
NVIDIA SHIELD Android TV
SoC
Tegra K1 (2.2 GHz 4x Cortex A15r3, Kepler 1 SMX GPU)
Tegra X1 (4x Cortex A57 + 4x Cortex A53, Maxwell 2 SMM GPU)
RAM
2 GB LPDDR3-1866
3 GB LPDDR4-3200
NAND
16/32GB NAND + microSD
16GB NAND + microSD + USB
Display
8” 1920x1200 IPS LCD
N/A, HDMI 2.0 4Kp60 Output
Dimensions
221 x 126 x 9.2mm, 390 grams
210 x 130 x 25mm, 654 grams
Camera
5MP rear camera, 1.4 µm pixels, 1/4" CMOS size. 5MP FFC
N/A
Battery
5197 mAh, 3.8V chemistry (19.75 Whr)
N/A, 40W Power Adapter
OS
Android 5.0.1
Android TV
Connectivity
2x2 802.11a/b/g/n + BT 4.0, USB2.0, GPS/GLONASS, mini HDMI 1.4a
2x2 802.11a/b/g/n/ac + BT 4.1/BLE, USB 3.0 + 2.0, HDMI 2.0 + HDCP 2.2, IR Receiver, Gigabit Ethernet
Launch Price
$299 (16GB/WiFi) + $59 (optional controller)
Basic: $199, Includes 1 SHIELD Controller
Pro: $299, Adds 500GB Hard Drive
The NVIDIA SHIELD smart TV platform comprises of three distinct products, the SHIELD console, the SHIELD wireless controller and the SHIELD remote.

The SHIELD is the main console, integrating a Tegra X1 SoC along with 3 GB of LPDDR4 DRAM and 16 GB of storage. I/O ports include two full-sized USB 3.0 host ports, a USB 2.0 micro-USB device port, GbE RJ-45 port, IR for universal remotes and 802.11ac 2x2 MIMO Wi-Fi with Bluetooth 2.1. It also includes a microSDXC slot. Video output is handled by a HDMI 2.0 port with HDCP 2.2 support.

The SHIELD Wireless Controller is the game controller bundled with the SHIELD console, and was first launched last year with the SHIELD Tablet. It uses Wi-Fi Direct for communication. A stereo headset jack and microphone are integrated. It also includes a rechargeable battery that can provide up to 40 hours of battery life.

Finally, the SHIELD Remote It is meant to be a replacement for the game controller in situations where single-handed operation is preferable. It uses Bluetooth for communication with the console. Like the game controller, a microphone and headset jack are included. The rechargeable battery is good for up to 4 weeks.



While the game controller and the console together retail in the basic package for $199, the SHIELD Remote is available separately for $50. Meanwhile after a slight snafu where it was announced back in April and then immediately pulled, NVIDIA is indeed offering a higher-end Pro SKU. SHIELD Pro model is similar to the SHIELD described above, except it adds an internal 500 GB hard drive into the mix and bundles a game - Borderlands: The Pre-Sequel! The Pro model is priced at $299.

Prior to diving into the details, let us take a look at the devices that NVIDIA is positioning the SHIELD Android TV against. Note that the two tables below are direct from NVIDIA's marketing material.



As we will see further down in the review, the above table is not far from the truth. In fact, except for NVIDIA claiming that their pulldown algorithm is enhanced compared to the competition, we tend to agree with everything. For the moment at least, NVIDIA pretty much has the 4K set top box to themselves.



NVIDIA claims a 34x raw performance increase compared to other OTT STB platforms. We won't endorse that particular number, but, in general, the performance of the SHIELD is miles ahead of the competition. The only other entry we find contentious is the availability of 24-bit / 192 KHz audio output. As we will see in the local media playback evaluation section, this is something of a moot point in most scenarios since the unit doesn't have licenses for decoding lossless HD audio. In any case, the above tables give an idea of where NVIDIA is positioning the SHIELD Android TV in the market.

The NVIDIA SHIELD Android TV also happens to be the first shipping product with the Tegra X1 SoC. We will first analyze the SoC and its performance in detail before moving on to Android TV in general and the SHIELD in particular.

Along with being NVIDIA’s first entry into the set top box/console market, the SHIELD Android TV also marks the launch of the latest generation Tegra SoC from NVIDIA, the Tegra X1. Formerly known by the codename Erista, NVIDIA first announced the Tegra X1 back at the company’s annual CES mobile presentation. In the long run NVIDIA has lofty plans for Tegra X1, using it to power their ambitious automotive plans – Drive CX visualization and Drive PX auto-pilot – but in the short run Tegra X1 is the successor to Tegra K1, and like K1 is meant to go into mobile devices like tablets and now set top boxes.

We’ve already covered Tegra X1 in quite some depth back at its announcement in January. But I wanted to recap the major features now that it’s finally shipping in a retail device, and in the process highlight what NVIDIA has capitalized on for the SHIELD Android TV.

Tegra X1 Mock-Up Die Shot

The Tegra X1 is something of a crash project for NVIDIA, as NVIDIA originally planned for the codename Parker SoC to follow Tegra K1. However with Parker delayed – I suspect due to the fact that it’s scheduled to use a next-generation FinFET process, which is only now coming online at TSMC – Tegra X1 came in on short notice to take its place. The significance of Tegra X1’s rapid development is that it has influenced NVIDIA’s selection of features, and what they can pull off on the TSMC 20nm process.

This is most obvious on the CPU side. NVIDIA of course develops their own ARMv8 CPU core, Denver. However the rapid development of Tegra X1 meant that NVIDIA was faced with the decision to either try to port a Denver design to 20nm – something that was never originally planned – or to go with an off-the-shelf ARM CPU design that was already synthesized on 20nm, and NVIDIA chose the latter. By pairing up a readily available CPU design with their own GPU design and supporting logic, NVIDIA was able to get Tegra X1 developed in time to roll out in 2015.

The end result is that for Tegra X1, NVIDIA has tapped ARM’s Cortex-A57 and Cortex-A53 CPU cores for their latest SoC. The use of standard ARM cores makes it a bit harder for NVIDIA to stand apart from the likes of Samsung and Qualcomm, both of which use A57/A53 as well, but as A57 is a very capable ARMv8 design it’s not a bad place to be in on the whole.

Overall NVIDIA is using a quad-A57 + quad-A53 design, similar to other high-end SoCs. The A57s have been clocked at 2.16GHz, a bit higher than other A57 designs we’ve seen, meanwhile we’ve been unable to get confirmation on the clockspeed of the A53 cores. Meanwhile rather than a somewhat standard big.LITTLE configuration as one might expect, NVIDIA continues to use their own unique system. This includes a custom interconnect rather than ARM’s CCI-400, and cluster migration rather than global task scheduling which exposes all eight cores to userspace applications. It’s important to note that NVIDIA’s solution is cache coherent, so this system won't suffer from the power/performance penalties that one might expect given experience with previous SoCs that use cluster migration.

Throwing in an extra bonus in NVIDIA’s favor of course is the fact that the SHIELD Android TV is a set top box and not a mobile device, meaning it has no power limitations an essentially unlimited thermal headroom. We’ll see how this plays out in benchmarking, but the biggest impact here is that NVIDIA won’t have to fight with TSMC’s 20nm process too much for SHIELD Android TV, and can keep their A57s consistently clocked high.

Meanwhile feeding Tegra X1’s CPU cores and GPU is a new 64-bit LPDDR4-3200 memory interface, which is attached to a sizable 3GB of RAM. LPDDR4 offers a good mix of bandwidth increases and power consumption reduction through a lower 1.1v operating voltage, and is quickly being adopted by the industry as a whole. Otherwise NVIDIA’s choice to stick to a 64-bit memory bus is expected, though it continues to be an interesting choice as it requires they fully exploit their memory bandwidth efficiency capabilities, as other SoCs geared towards tablets and larger device (e.g. Apple A8X) come with larger memory buses.

GPU

On the GPU side, Tegra X1 features one of NVIDIA’s Maxwell architecture GPUs (the X being for maXwell, apparently). As a GPU architecture Maxwell marks the start of something of a new direction for NVIDIA, as NVIDIA designed it in what they call a mobile-first fashion. By starting in mobile and scaling up to the desktop, NVIDIA is integrating deep power optimizations into their GPU architectures at an earlier stage, achieving better power efficiency than scaling down desktop GPUs. This has also led to the gap between desktop and SoC implements of NVIDIA’s latest and greatest GPUs shrinking, with Tegra X1 showing up on a bit more than a year after Maxwell first appeared in desktop GPUs.

In any case, with Maxwell already shipping in desktops, it has proven to be a powerful and formidable GPU, both on an absolute performance basis and on a power efficiency basis. Though it’s a bit of circular logic to say that NVIDIA is intending to exploit these same advantage in the SoC space as they have the desktop space – after all, Maxwell was designed for SoCs first – Maxwell’s capabilities are clearly established at this point. So from a marketing/branding perspective, NVIDIA is looking to capitalize on that for Tegra X1 and the SHIELD Android TV.

Overall the X1’s GPU is composed of 2 Maxwell SMMs inside a single GPC, for a total of 256 CUDA cores. On the resource backend, NVIDIA has gone from 4 ROPs on Tegra K1 to 16 on X1, which won’t lead to anything near a 4x performance increase, but it is very important for NVIDIA’s desires to be able to drive a 4K display at 60Hz. And while NVIDIA isn’t listing the clockspeeds for the SHIELD Android TV, we believe it to be at or close to 1GHz based on past statements and the device’s very high thermal threshold.

Meanwhile from a feature standpoint Maxwell is as modern a SoC GPU as you’re going to find. Derived from a desktop GPU, it features support for all modern Android APIs and then some. So not only does this include OpenGL ES 3.1 and the Android Extension Pack, but it supports full desktop OpenGL 4.5 as well. On paper it is also capable of supporting Khronos’s forthcoming low-level Vulkan API, though we’re still a bit early to be talking about Vulkan on mobile platforms.

Also introduced on the Maxwell architecture – and by extension Tegra X1 – is NVIDIA’s latest generation of color compression technology, which significantly reduces NVIDIA’s memory bandwidth needs for graphics workloads. NVIDIA’s memory bandwidth improvements are in turn going to be very important for Tegra X1 since they address one of the biggest performance bottlenecks facing SoC-class GPUs. In the case of memory bandwidth optimizations, memory bandwidth has long been a bottleneck at higher performance levels and resolutions, and while it’s a solvable problem, the general solution is to build a wider (96-bit or 128-bit) memory bus, which is very effective but also drives up the cost and complexity of the SoC and the supporting hardware. In this case NVIDIA is sticking to a 64-bit memory bus, so memory compression is very important for NVIDIA to help drive X1. This coupled with a generous increase in memory bandwidth from the move to LPDDR4 helps to ensure that X1’s more powerful GPU won’t immediately get starved at the memory stage.

The other major innovation here is support for what NVIDIA calls “double speed FP16”, otherwise known as packed FP16 support. By packing together two compatible low-precision FP16 operations, NVIDIA is able to double their FP16 throughput per CUDA core relative to the Tegra K1, which coupled with the overall increase in CUDA cores leads to a very significant improvement in potential FP16 performance. Though this feature is perhaps most strongly aimed at NVIDIA’s Drive platforms, Android itself and a good chunk of Android games still use a large number of FP16 operations in the name of power efficiency, so this further plays into X1’s capabilities, and helps NVIDIA stretch X1’s performance a bit further for gaming on the SHIELD Android TV.

Last but certainly not least however is Tegra X1’s media capabilities, which more than anything else are the heart and soul of the SHIELD Android TV. By being one of the newest SoCs on the block the Tegra X1 is also one of the most capable SoCs from a media standpoint, which is allowing NVIDIA to come out of the gate as the flagship Android TV device.

Chief among these is support for everything NVIDIA needs to drive 4K TVs. Tegra X1 and SHIELD Android TV support HDMI 2.0, allowing it to drive TVs up to 4Kp60, and with full quality 4:4:4 chroma subsampling. NVIDIA also supports the latest HDCP 2.2 standard, which going hand-in-hand with HDMI 2.0 is (unfortunately) required by 4K streaming services such as Netflix to protect their content, as they won’t stream 4K to devices lacking this level of DRM.

On the backend of things, Tegra X1 brings with it support for H.264, VP9, and H.265 (HEVC) decoding. The latter two are just now appearing in SoCs, and as higher efficiency codecs are going to be the codecs of choice for 4K streaming. Consequently then Tegra X1 is capable of decoding all of these codecs at up to 4K resolution at 60fps, ensuring that it can decode not just 24fps movie content, but 30fps and 60fps TV content as well. As one final benefit, NVIDIA is also supporting full hardware decoding of 10-bit (Main 10) H.265 video, which means that the Tegra X1 and SHIELD Android TV will be capable of handling higher quality, higher bit depth content, including forthcoming HDR video.

NVIDIA SHIELD SoC Comparison

SHIELD Tablet (Tegra K1)
SHIELD Android TV (Tegra X1)
CPU
4x Cortex A15r3 @ 2.2 GHz
4x Cortex A57 @ 2.16GHz?
4X Cortex A53@ ?GHz
GPU
Kepler, 1 SMX (192 CUDA Cores)
@ ~800MHz
Maxwell, 2 SMMs (256 CUDA Cores)
@ ~1000MHz?
ROPs
4
16
Memory
2 GB, LPDDR3-1866
3 GB, LPDDR4-3200
Memory Bus Width
64-bit
64-bit
FP16 Peak
365 GFLOPS
1024 GFLOPS
FP32 Peak
365 GFLOPS
512 GFLOPS
Manufacturing Process
TSMC 28nm
TSMC 20nm SoC
Taken in overall, the use of the Tegra X1 puts the SHIELD Android TV in a very interesting position. From a raw graphics standpoint the system is arguably overpowered for basic Android TV functionality. Even though this is a SoC-class Maxwell implementation, the basic Android TV UI does not heavily consume resources, a design decision mindful of what most other SoCs are capable of. But this also means that NVIDIA should have no trouble keeping the Android TV UI moving along at 60fps, and if they do struggle then it would certainly raise some questions given just how powerful Tegra X1’s GPU is.

Gaming on the other hand still needs all the GPU processing power it can get, and to that end NVIDIA is delivering quite a bit. NVIDIA still has to live with the fact that Tegra X1 isn’t close to the performance of the current-generation consoles, with SoCs having just recently surpassed the last-generation consoles, but by being the most powerful SoC in the Android TV space, it means NVIDIA can at least deliver an experience similar to (and likely a bit better than) the last-generation consoles, which is still a bit step up.

Otherwise from a media decode standpoint, Tegra X1 is the perfect fit for the device that will be the flagship Android TV box. By supporting all of the latest codecs and display standards, NVIDIA is in a good position going forward to work with the increasing number of 4K TVs and the various over-the-top media services that will be utilizing H.265 to drive their 4K streaming. The fact that NVIDIA is pushing media capabilities so hard for today’s launch is not a mistake, as it’s likely to be their most useful advantage early in the device’s lifetime.

From an editorial perspective, the SHIELD Android TV may be one of the most frustrating devices we’ve worked on in recent history. Simply put, the Android TV market is still a tiny market. Google’s Nexus Player is most of the market right now, and only very recently have other Android TV devices such as the Forge TV and SHIELD Android TV reached the market.

As a result, figuring out what to compare the SHIELD Android TV to and how to present it has been an interesting challenge. A set top box is not a mobile device, and while they share similar OSes and the same families of SoCs, that does not make them identical devices. At the same time however, if we restrict ourselves to just Android TV devices, it would be a very limited and uninteresting comparison. The Nexus Player is a quad-core Intel Atom, but only includes 1GB of RAM, among other limitations.

Ultimately it’s clear that the SHIELD Android TV is heavily overspeced compared to other Android TV devices – no one else is pursuing this premium market – so instead we’re going to focus on looking at benchmarked performance relative to the newest generation of SoCs in the latest iOS and Android tablets. This is by no means a fair matchup and we need to be clear about this – the SHIELD Android TV has no throttling or power constraints, no need to balance out energy efficiency – but it at least gives us some idea of how the device and Tegra X1 compare to other products. Just don’t expect to see a Tegra X1 tablet perform this well. And in the meantime, some of the results may surprise you.

As always for an Android device review, we'll start off with our browser benchmarks. SHIELD Android TV doesn’t actually ship with a browser – we had to sideload Chrome – but these are among our most flexible benchmarks and help put performance in context of more than just Android devices.

Among Android devices, the SHIELD Android TV stands alone, as you’d expect. Without any throttling to hold it back, it leads over Tegra K1, Snapdragon S810, and Exynos 7420 over all 3 web benchmarks. That said, even with its unrestricted Cortex-A57 CPU cores, we also find that Apple’s A8X-based iPad Air 2 is a close match in Octane and WebXPRT, just edging out the SHIELD Android TV and being edged out respectively. Meanwhile for anyone curious how this compares to high-end x86 tablets like the Surface Pro 3, well even SHIELD Android TV isn’t quite up to par with those devices at this time.

Moving on, we have Basemark OS II 2.0, which should give a better picture of CPU performance in addition to overall device performance.

Overall, performance under Basemark still slightly favors the iPad Air 2. SHIELD Android TV easily takes the second spot, but it’s not enough to catch Apple’s tablet.

Looking at the subscores, we can see why this is. SHIELD Android TV only fares decently under the System test, but not well. The big surprise here is not the iPad, which always does well, but the fact that the SHIELD is so far behind the Galaxy S6, which features a similar CPU setup. As this sub-test pushes both the CPU and memory, we may be seeing something related to the implementation differences between Tegra X1 and Exynos 7420, or it may just be an Android TV-inspired difference.

However the memory score is particularly bad, coming in behind even the last-generation SHIELD Tablet. As this is a NAND test, what we're likely seeing is a consequence of the SHIELD's poor random performance, something we'll dive into a bit later in our detailed look at NAND performance.

On the other hand, graphics and web performance are outstanding. We had certainly expected the SHIELD to do well in graphics given what Maxwell is capable of – it is a graphics monster unlike any other current SoC – but the web test is a pleasant surprise. The combination of using Android TV’s built-in web view and the lack of any real throttling likely play a big part here, and although Android TV doesn’t ship with a standard web browser, this bodes well for any apps making use of web view and Javascript.

Our next system benchmark is PCMark, which does a number of basic benchmarks designed to stress various aspects of the device in everyday workloads like video playback, web browsing, text editing, and photo editing. This tends to test every aspect of a mobile device, unlike microbenchmarks that can often miss aspects of the system that can affect performance.

With the exception of the Writing subtest, where the SHIELD Android TV and second-place device are kind of close, PCMark is a runaway victory for the SHIELD Android TV. Once again we’re almost certainly seeing the benefits of the box’s aggressive performance since it doesn’t need to throttle down, or even be conservative on clockspeeds for power purposes. In which case it gives us an interesting look at what Cortex-A57 can do when not held back.

Overall, CPU/system performance is more or less what one would expect based on the design of the SHIELD. As a set top box with a quad-core A57 implementation under the hood and the cooling to let it run wild, SHEILD is frequently A57 at its best. Which means it’s going to easily surpass other A57 devices in most situations, but it also means that even with its unrestricted performance, Apple’s A8X processor and its tri-core “Enhanced Cyclone” CPUs still serve as a reminder of those times where A57 struggles against Enhanced Cyclone’s high-IPC design.

For our final look at system performance, let’s take a quick look at the SHIELD's built-in NAND performance with AndroBench 4.0.

Though we only have a few AndroBench 4.0 results compiled so far, it’s enough to paint a decent picture. For sequential tests the SHIELD’s built-in NAND fares relatively well. It’s not enough to top the Galaxy S6 and its UFS flash, but it’s keeping up with the pack. However random performance is quite poor; the SHIELD Android TV is at the bottom of the chart in both cases, below even the SHIELD Tablet. UFS definitely gives the Galaxy a big benefit here, but the SHIELD could stand some improvements. However I’m not sure how much that matters to NVIDIA, as the SHIELD is clearly designed to lean on external storage via microSD/USB for users who end up using it for storage-intensive needs such as gaming as opposed to basic set top box streaming.

While the SHIELD Android TV and the underlying Tegra X1 SoC are by no means slouches on the CPU side of matters, ultimately NVIDIA is still just another ARM Cortex implementer. On the other hand when it comes to GPUs, this is where NVIDIA truly shines. As NVIDIA is first and foremost a GPU company, and as a design philosophy always invests more time and die space into GPUs than any other SoC builder (save perhaps Apple X-class SoCs), they have always led the pack on GPU performance. And with the Tegra X1 packing a 256 CUDA core implementation of the very potent Maxwell GPU architecture, an estimated 1GHz clockspeed, and all the power and cooling it needs to keep from throttling, all of the ingredients are in place for a very strong showing from NVIDIA for GPU performance.

If there’s any real downside for NVIDIA and the SHIELD Android TV here, it’s that the Android GPU benchmarking situation hasn’t really caught up with what their GPUs are capable of. The standard benchmarks work, but game benchmarks are virtually non-existent, even in the AA and AAA games NVIDIA has helped bring over to the Android/SHIELD ecosystem. So we can’t for example look at the performance of The Talos Principle in the same way as we can the PC today.

Anyhow, we’ll start off with 3DMark’s Ice Storm Unlimited benchmark.

The results here pretty much speak for themselves, especially in the all-GPU graphics sub-score. SHIELD Android TV is 50% faster than the Surface Pro 3 and almost twice as fast as other devices like the iPad Air 2 and the last-generation SHIELD Tablet. Graphics workloads tend to be the most punishing from a heat and power standpoint, and hence are the most likely to get throttled. This really lets the SHIELD and its SoC open up here. At the same time, even in the physics score and the composite overall score, the SHIELD is well in the lead thanks to this combination of factors.

Up next we have BaseMark X 1.1.

Once more it’s a clean sweep for the SHIELD. Apple’s iPad Air 2 tends to be the second-place finisher, thanks to Apple’s own significant investment in GPU resources, the SHIELD gets yet more resources and the power to fully exploit them. With all of that said, the one thing that does surprise me a bit here is that even the SHIELD can’t crack 60fps on Dunes and Hangar; BaseMark X will likely take one more generation before its tests can be completely beaten.

Our final GPU benchmark is GFXBench.

Starting first with the benchmark’s high-level tests, we once again find the SHIELD well in the lead. Of particular note here, the SHIELD Android TV becomes the first Android device to break 60fps on Manhattan, something that as recently as a generation ago seemed impossibly far away.

The low-level tests meanwhile offer us an interesting look at SHIELD and Tegra X1 that the high-level tests don’t provide. The ALU test for example drives home the point of just how much in the way of shading resources Tegra X1 has at its disposal (at least when unrestricted), and is a big reason why the SHIELD is doing so well here. On the other hand while NVIDIA still takes the top spot in alpha blending, the lead over the iPad Air 2 isn’t nearly as great, thanks in large part to the iPad’s relatively large 128-bit memory bus. Ultimately SHIELD doesn’t struggle here, but it’s an interesting point of comparison since it shows one of the only cases where SHIELD isn’t a run-away winner, and what kind of graphics workload may eat into its otherwise ridiculous advantage.

On the last batch of subtests, I’m going to stop again with the fill rate test just to point out another interesting design decision for Tegra X1 and the SHIELD. With NVIDIA banking so much on the set top box’s ability to drive 4Kp60 TVs, NVIDIA needs to push a lot of pixels to get there, as 4K is four-times as many pixels as 1080p. For this reason Tegra X1 is paired with 16 ROPs, giving it low-end PC desktop-like pixel throughput, and of course a huge advantage in the GFXBench fill rate test. And though this fill rate will help with games as well, it’s keeping up with the Android UI at 4Kp60 that is the most important reason for all of this fill rate performance.

Wrapping things up, what else is there to say about the SHIELD Android TV’s GPU performance? What we’re looking at here is twice as fast (or more) than the best phones and tablets today, a combination of the Tegra X1’s very strong GPU design and the set top’s practically unlimited energy and cooling capabilities. Overall NVIDIA is following the path they started long ago on Tegra, always favoring strong GPU performance, leading to the incredible performance we’re seeing here.

With that said, given NVIDIA’s decision to focus on the Android TV aspects of the SHIELD Android TV first and foremost – and not gaming – it’s also fair to say that the SHIELD is overpowered for Android TV work. Other than keeping up with the basic pixel fill needs of 4K, the real power of the box’s GPU is going to be left untapped by Android TV (especially on the ALU side). Which makes all of this humorously absurd in a way, but it’s also why SHIELD Android TV isn’t just an Android TV box. The device’s GPU performance will be put to good use with gaming, though stepping outside the world of benchmarks for a second, the bigger challenge NVIDIA faces is not delivering high performance, it’s delivering games that make full use of that performance.

The focus today (coinciding with Google I/O) is obviously on Android TV. Google, having learnt from its previous Google TV initiative, brought forward the Android-based Android TV, a new Smart TV initiative, towards the end of 2014. It delivers a comprehensive app ecosystem across multiple devices - both first screen and second screen.

Google's experience with voice search and personalized recommendations, combined with the users' Google Play movie and music collection, puts many pieces of the puzzle already in place. The success of Chromecast has led to Google Cast - a feature where an Android TV device can also act as a casting sink.

The rich UI used by Android TV is the Leanback Launcher. It is a 10-ft. UI combining large icons with easy and logical navigation options. The game controller supplied with the SHIELD works very well for navigation. Typing in text is a pain, which is why NVIDIA (and Google) are pushing voice search so hard for the platform, with both the Controller and Remote including microphones for that feature. Otherwise the input problem can easily be solved by a wireless keyboard / mouse combo - since Android TV supports any USB device adhering to the standard Android HID specifications.

Voice search can also be used within various apps, depending in part on how developers choose to implement it. In addition, it can also be used for cross-app searches from the Android TV launcher. Cross-app searches are meant to promote an open smart TV ecosystem, and as the name implies allows the Android TV search process to query multiple services for results, something that is especially handy if you want to look for a TV show or movie across several services. Developers do need to enable their participation in this feature, and conversely the end-user has the ability to configure the apps that are part of the search process.

Switching gears to the interface, the Android TV home screen starts with a 'Recommendations' row. End users can prevent certain apps from providing recommendations by turning off their notifications. However, it doesn't seem to be possible to remove the 'Recommendations' row entirely.

In addition to VoD from services such as Google Play Movies, CinemaNow, MubiTV, Netflix, Hulu Plus etc., Android TV also brings in support for live streams of channels using SlingTV and Live Channels. The latter app in particular is an interesting addition to the Android TV ecosystem since it makes Android TV devices (including the SHIELD Android TV) a bonafide TV receiver, takeing TV tuner boxes such as SiliconDust HDHomeRun and interfacing their IP output feed with Live Channels' own unified UI.

Major television networks are also expected to announce their own Android TV apps. Opposite today's launch at Google I/O, Google has announced that HBO, CBS, and FOX are all bringing video services to Android TV, making their content available OTT.

Meanwhile, discussing input a bit more, Google also has an Android app to enable a smartphone or tablet to act as a remote control for an Android TV device. It is obviously compatible with the SHIELD also.

[embedded content]

The video above shows the various settings available in the NVIDIA SHIELD Android TV. Subjectively speaking, turning off the Notifications / Recommendations provides a cleaner and more minimalist interface. The cross-app voice search remains available to provide recommendations when the user wants them.

The announcement of the SHIELD Android TV box generated a lot of interest amongst media streaming enthusiasts. It has continued to this date. Given that most of them prefer local media playback to OTT streaming, there has been marked interest in the local media playback capabilities of the unit. In this section, we attempt to set the expectations right on the various relevant aspects.

Display Refresh Rate

The Android TV framework forces the interface and most apps to run at 60 Hz. Obviously, a 24 fps film needs to be pulled-down with a 3:2 cadence to let the display be refreshed at 60 Hz. This creates a judder effect. Apps such as TVHZ were created to resolve this issue, but needs manual intervention prior to media playback. Kodi's currently existing 'sync refresh rate to playback frame rate' option doesn't work, but a fix is probably coming soon.

Codecs Licensing

Unlike a PC, the SHIELD Android TV is an embedded system. Therefore, codec support involves NVIDIA signing licensing deals. For example, support for Dolby Digital / Dolby Digital Plus requires deals with Dolby Laboratories, while DTS / DTS-HD support requires deals with DTS. On the video side, H.264 support, for example, requires a deal with MPEG-LA. Each of these deals ends up increasing the end cost for the consumer. In order to hit an acceptable price point while ensuring all necessary components for OTT streaming (SHIELD's primary market) are in place, NVIDIA has signed deals for the following audio/video codecs only:

H.264
H.265
VP9
Dolby Digital
Dolby Digital Plus
This means that the native Android Video Player can only play back the above codecs (in addition to the free-to-decode / play ones such as PCM audio). This also means that the SHIELD Android TV will not be doing any HD audio bitstreaming in the near future unless things chance on the licensing front.

That said, players such as Kodi, MX Player etc. can opt to use pure software decoding when hardware decoding is not available. It is also possible for app vendors to purchase the license themselves and then work with NVIDIA to get hardware acceleration / support for that. For example, SiliconDust (the vendor behind HDHomeRun) is doing it with their Live TV app in order to get hardware decoding enabled for MPEG-2.

Attempting 480i60 MPEG-2 Playback with the Native Android Video Player

Video Post Processing

Deinterlacing and pull-down detection / IVTC are essential for watching certain live TV channels and other interlaced content. NVIDIA only guarantees video post processing for the licensed codecs that go through their hardwrae decoder. Third-party players will need to work with NVIDIA to ensure that any software decoded streams are correctly hooked up to the post-processing chain.

We tried processing the HQV Benchmark videos on the SHIELD to get an objective evaluation of the SHIELD's post-processing capabilities, but unfortunately the MPEG-2 encoded streams were not processed properly when decoded in software on Kodi.

Experimenting with Kodi

The Kodi 15.0 beta 1 APK is available for sideloading on to the SHIELD Android TV. On the bitstreaming side, we could only select DTS and Dolby Digital, and Kodi had no problems bitstreaming those streams.

We played back our test streams from a Samsung T1 portable SSD attached to the USB 3.0 port. HEVC streams played back with hardware acceleration inside the Kodi interface, but Kodi had trouble with TS files. For hardware-accelerated codecs, the power consumption at the wall was around 6 W. For software-decoded ones such as our 1080i60 VC-1 clip, the power consumption shot up to 11.5 W.

The SHIELD Android TV / Kodi combination has absolutely no trouble with the vanilla H.264 files that people usually rip their Blu-rays to. Fortunately, despite the lack of MPEG-2 and VC-1 licenses, Kodi's software decode is efficient enough to not cause frame drops. The absence of deinterlacing is an issue, but that should hopefully get resolved soon.

Based on our evaluation, the SHIELD Android TV is definitely not a comprehensive HTPC replacement - particularly from the local media playback viewpoint. That said, it does have support for all major OTT services and Live TV as well as future DVR capabilities (thanks to Android TV). For a certain set of users, it is possible that the SHIELD can replace their HTPC. However, one needs to remember that the unit is an embedded system with plenty of constraints and doesn't have the same openness and flexibility that a HTPC has to offer.

The NVIDIA SHIELD is currently the only Netflix 4K-certified set-top box in the market. This certification involves two important requirements:

Presence of a HDMI 2.0 port with HDCP 2.2 capability
Presence of a hardware decoder for HEVC Main and Main10 profiles
NVIDIA was the first in the PC space to bring HDMI 2.0 together with HDCP 2.2 support as well as a hardware decoder for HEVC in the GTX 960. They are also extending this lead to the SoC space with the Tegra X1. Thus, the NVIDIA SHIELD Android TV has turned out to be the first set-top box to meet Netflix's criteria for 4K certification.

The UltraHD-capable Netflix streaming plan is the highest-end one, coming in at $11.99 per month before taxes. If the SHIELD is connected to a HDMI 2.0 4Kp60 sink supporting HDCP 2.2 and the Netflix account is on a supported plan, the Netflix app's UI presents a row of Ultra HD 4K streams in addition to the generic categories. We tested out Netflix 4K on a Samsung HU6950 without an AV receiver inbetween.

Netflix has a special test stream that shows the characteristics of the currently playing stream. As expected, the SHIELD had no trouble in getting to the 4K encode.

In the adaptive streaming process, we came across a host of different encodes. They are listed in the gallery below.

Regular readers of our HTPC reviews might remember that the Windows 8.1 Netflix app tops out with a 5.8 Mbps 1080p H.264 stream. On devices with HEVC support, it appears that this is replaced by a 5.16 Mbps HEVC Main10 stream at the same resolution. There is also a higher bit-rate version (6.96 Mbps) with similar characteristics. Beyond that, we have the 4K stream at 9.6 Mbps. Unfortunately, we don't know the exact characteristics of the encode, but, based on the immediately preceding lower bit-rate streams, it is probably a HEVC Main10 encode too.

The Netflix app gives us an indication that the SHIELD has no trouble with HEVC. In order to confirm this, we put our HEVC test suite through Android's native Video Player.

[embedded content]

The video shows perfect playback of 4Kp24, 4Kp25 and 4Kp30 HEVC Main and Main10 profile streams. For 4Kp60, we only have Main profile videos, and the SHIELD has no trouble with that.

On one hand, it is nice to see the SHIELD Android TV's 4K Netflix capabilities as well as support for high frame-rate HEVC playback in a power-efficient system. Though the 4K TV adoption rate is still very low - it's the start of what will be a long process - of anything and everything NVIDIA needed to do to secure their spot as the set top box to have for 4K TVs, getting Netflix 4K support in place is it.

On the other hand, it also reminds us of the sorry state of HTPCs with respect to HDMI 2.0, HDCP 2.2 and HEVC playback. For enthusiasts, it is imperative that PCs catch up soon, given that local media streaming is not a focus point for the SHIELD.

NVIDIA's Tegra lineup has traditionally differentiated itself from a host of other ARM-based SoCs in the target market with the in-house GPU. In the Tegra X1, we have a GPU based on the Maxwell family, and as benchmarks showed, the performance is very good. Broadly speaking, next to 4K Netflix support, NVIDIA considers gaming capabilities to be the trump card for the SHIELD when compared to other OTT STBs.

With that said, you’re not going to be seeing a lot of official talk from NVIDIA about gaming on the SHIELD Android TV today, and that’s for two reasons. First and foremost is simply because not all of the pieces are ready. The commercial GRID service does not launch until next month, and while SHIELD can access the current beta service, it goes without saying that half of what we write on GRID will be made obsolete in 5 weeks anyhow. Meanwhile some of NVIDIA’s well-promoted AA and AAA games are ready – games like The Talos Principle and Doom 3: BFG – while other games like Borderlands: The Pre-Sequel and Crysis 3 are not here.

The second reason meanwhile is that given the SHIELD’s launch amidst Google I/O, NVIDIA is also making the conscientious decision to focus on those features that are most relevant to the Google I/O crowd and the contents of Google’s presentation. With the device’s announcement at GDC 2015, NVIDIA played to gaming amidst a gaming crowd, while for the device’s launch they’re playing to everything that’s amazing about Android TV, the Android TV ecosystem, and 4K TV.

The point being that NVIDIA hasn’t forgotten about gaming, but the SHIELD Android TV’s gaming capabilities aren’t what NVIDIA is focusing on first. Expect to hear a lot more about gaming later in June once the GRID commercial service is up and running.

As for today’s launch, while gaming isn’t in the forefront, that doesn’t mean it doesn’t work. As we briefly mentioned earlier several high-profile games are already available, so we’ve still had a chance to look at what NVIDIA’s latest SHIELD can offer for gaming.

A big part of NVIDIA’s long-term gaming plans for the SHIELD family of devices involves working with game developers to ensure that Android gaming grows beyond the casual, free-to-play titles that are currently popular. As a product of these dev-relation efforts, a number of games are going to be introduced in the Play Store to bring out the gaming prowess of the Tegra X1. We had the chance to play around with a few such as The Talos Principle, Hotline Miami, Luftrausers, Doom 3 : BFG Edition, War Thunder and family-friendly casual games such as JUJU.

The above screenshot shows the level of graphics that provides for smooth playable frame rates in the SHIELD. Based on what I've seen, I don't believe the internal rendering resolution is 1080p in The Talos Principle, but I suspect it's not too far off.

With NVIDIA carrying over the SHIELD gamepad from last year's SHIELD Tablet launch, playing games on the SHIELD Android TV works about as well as you'd expect for a second-generation effort. The performance of the set top box is still closer to the last-generation consoles than the current-generation consoles, and graphics quality matches up accordingly. NVIDIA is well aware that they can't compete with the game consoles for first-run AAA games, so their focus here is going to be on a sort of best-of-the-best approach of bringing older, well received games to the console and a user base NVIDIA believes is distinct from the traditional game console crowd.

Shifting gears for a bit, we also have the matter of casual games. From a technical standpoint, it goes without saying that casual games such as JuJu do not pose much of a challenge for the SHIELD.

In addition to the above, NVIDIA has indicated that more than 20 new titles are coming exclusively to NVIDIA SHIELD in the coming months.

We also recorded power consumption at the wall while playing the above two games on a 4Kp60 display. In both cases the SHIELD consumed around 19.4 W on an average, considerably more than the power consumed in the media playback process.

Finally, one of the interesting features is the ability to live-stream to Twitch or record game-play using the SoC's hardware encoder. We tested the latter feature out. The resultant recordings were placed under /sdcard/Movies/Game Recordings. Irrespective of the playing resolution, the recording is always a 2 Mbps 854x480 video at 30 fps (encoded in H.264). The audio is a 128 kbps 2-channel AAC stream. The sample we recorded has been uploaded to YouTube and embedded below. Full MediaInfo details are available in the YouTube description.

[embedded content]

In order to see what the power and thermal characteristics of the SHIELD Android TV are like, the device was tested in two scenarions:

1080p60 HDMI output to Pioneer VSX-32, connected to a Sony KDL46EX720 46" 1080p TV. Connected to a wired network, with a Samsung T1 SSD hanging off the USB 3.0 port
4Kp60 HDMI output to a Samsung HU6950 40" 4K TV. Connected to a wireless network, with a Samsung T1 SSD hanging off the USB 3.0 port.
The table below summarizes the important power consumption numbers.

NVIDIA SHIELD Android TV Power Consumption
Activity
Avg. Power (W)
Idle (Scenario 1)
3.6 W
1080p Netflix Streaming (Scenario 1)
4.6 W
1080p YouTube Streaming (Scenario 1)
4.7 W
Kodi Playback (Hardware Accelerated 1080p60 H.264) (Scenario 1)
6.5 W
Kodi Playback (Software Decoding 1080i60 VC-1) (Scenario 1)
10.4 W

Idle (Scenario 2)
4.2 W
4K HEVC Playback (Scenario 2)
9.1 W
4K Netflix Streaming (Scenario 2)
10.3 W
Gaming (Scenario 2)
19.4 W

Since the gaming scenarios stressed the at-wall power consumption heavily, we decided to run the GFXBench battery life test which puts the T-Rex benchmark in an infinite loop. After 2 hours, we took a thermal image of the unit (oriented vertically with the SHIELD stand).

The thermal solution is excellent, and the frame rates were consistent across all the benchmark runs. Thanks to the low-power SoC, the chassis temperature was just 34 C (ambient at 23 C). The fan noise was audible only when we kept our ears against the vents in the back panel.

Moving on to the business end of the review, we split up the positives and negatives into two sections - one for Android TV itself, and the other for the SHIELD.

The NVIDIA SHIELD Android TV is based on the Tegra X1, which is, without doubt, a very powerful SoC. Ostensibly designed for mobile platforms - particularly tablets - Tegra X1 none the less finds itself in a very interesting (and perhaps unexpected) role as the heart of a set top box. In the SHIELD Android TV, the thermal limits are relaxed and there is no battery life to worry about. Therefore, the SoC performance handily surpasses the currently existing competition in the over the top set top box market.

Android TV

A good 10-ft UI is essential for interaction on a TV. Subjectively speaking, the Leanback Launcher provides an acceptable experience.
Android TV enables cord-cutting with a "Live Channels" app that takes advantage of TV tuners with IP interfaces and provides an interface to watch them on a television (allowing the TV tuners / antenna to be placed somewhere suitable for good reception and not necessarily near the TV).
Google's voice search (with cross-app searching capabilities) is quite advanced.
Android TV comes with Google Cast - a feature that allows devices like the SHIELD to act as Chromecasts
Android TV comes with an improved selection of relevant apps compared to Google TV from a few years back.
Android TV is more open than any other Smart TV platform - it brings along a lot of the advantages of the Android ecosystem
Android HID support ensures many USB peripherals such as mice, keyboards and webcams are compatible with Android TV devices
Needs Fixing:
Android TV needs better configurability - for example, users should be allowed to change the order of rows in the Leanback UI or even remove some of them altogether. Not everyone wants ad-like 'Recommendations' as soon as they power up the unit. On Android, the 'Notifications' feature is often abused to push advertisements. Users need more control. The option to control the fading and distance between each row in the launcher would also be nice to have.
The Android TV framework needs to do away with forcing 60 Hz display refresh rate for the system. Ideally it should be synced to the frame rate of the content being played back (whenever possible). 3:2 pulldown of 24 fps material for display at 60 Hz creates judder that could be irksome for certain consumers.
Android TV could do with better stability - We encountered a few 'Leanback Launcher has stopped' messages. In certain scenarios, users would also appreciate better responsiveness - for example, the 'fetching recommendations' at startup doesn't allow the user to navigate to the rows further down for a few seconds
SHIELD

Netflix 4K streaming is flawless. It is the only 4K Netflix certified STB we are aware of. Everything so far has been using in-built Smart TV apps.
The Android TV support is comprehensive. Microphones and headset ports in both the gaming controller as well as the Remote enhance the user experience when combined with the voice search capabilities. The high-performance SoC ensures smooth navigation in the UI.
The SHIELD has full support for decoding HEVC Main and Main10 profile streams. These are the only H.265 profiles that matter for end consumers
Unlike some other 'HDMI 2.0'-capable SoCs, the SHIELD has extensive HDMI 2.0 compatibility with HDCP 2.2 support. It is also firmware upgradable to HDMI 2.0a (HDR extensions). In fact, it fits all our criteria for a future-proof 4K HDMI source.
The CEC capability works seamlessly. A swipe of the NVIDIA logo on the gaming controller and everything in the playback chain turns on.
The bundled gaming controller and the SoC's GPU performance enables Android gaming to go beyond the current casual, free-to-play ecosystem
The device has excellent thermal performance and acceptable / reasonable acoustics despite being an actively cooled device
Needs Fixing:
The AV receiver compatibility list needs to be expanded. Dolby Digital Plus bitstreaming (from Netflix) was a no-go with a Pioneer VSX-32, though such cases will soon get fixed via firmware updates.
NVIDIA has skimped on licensing for various audio and video codecs keeping the target market in mind. Only H.264, H.265 and VP9 decode have been licensed on the video side. On the audio side, we only have Dolby Digital and Dolby Digital Plus. The absence of HD audio bitstreaming is particularly disappointing, given the capabilities of the core platform. NVIDIA talked about making available a 'codec pack' in the Play Store for users needing hardware acceleration for certain codecs. We will have to see how that plays out.
NVIDIA's experience with HTPC GPUs has not been translated to the SHIELD Android TV due to the limitations of the Android TV framework. We expected NVIDIA to work around that, providing differentiation aspects with local media streaming and video post processing in addition to the 4K Netflix feature.
It would be nice to have better compatibility with local playback apps (like Kodi, MX Player and VLC). NVIDIA indicated that they are working with the developers already. Hopefully, we should see local media playback apps behave better with the Tegra X1 in the coming months.
Moving on to the pricing aspect, the non-Pro model that we reviewed here is priced at $199. This includes the gaming controller (other Android TV boxes treat it as a separate purchase) and a high-speed HDMI cable (supporting 4Kp60 signals). Meanwhile, for a short introductory period, the $199 price point will include a $30 Google Play store credit and a 90-day subscription ($30 value) to Google Play Music All Access.

Otherwise, not reviewed today is the Pro at $299, which throws in a 500GB internal hard drive and a bundled copy of Borderlands. The Pro's further $100 price tag is no doubt going to draw some comparisons to the current-generation consoles - and for good reason, witht he 500GB Xbox One starting at just $50 more - and may be a harder sale for NVIDIA. The large hard drive is definitely wel suited towards gaming, however possibility of also using it for DVRing TV programming through the Google Live Channels app offers an interesting alternative for all of that space.

Final Words

The SHIELD Android TV is a reasonably priced premium 4K over-the-top set top box with gaming performance that well exceeds any other STB. In that respect, given the rising importance of OTT streaming and casual gaming in the living room, NVIDIA has achieved what it set out to do.

However, HTPC enthusiasts expecting the SHIELD to be a device that combines leading-edge OTT capabilities with perfect local media playback will be disappointed. The constraints imposed by the closed nature of an embedded system (compared to PCs) mean that the situation is unlikely to alter in a major way in the near future.

Consumers need to get their expectations right - the SHIELD Android TV needs consideration only if OTT streaming (4K Netflix, in particular) and gaming credentials are important. Keep in mind - if you are getting it for 4K Netflix, ensure that each HDMI port in your display chain is capable of both 4Kp60 and HDCP 2.2.

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