Note: All of this is the work of soniCron, I only reposted this thread here with his explicit permission so that we can have a thread that only deals with the 6P.
The original thread can be found here: http://forum.xda-developers.com/nexu...ernor-t3269557
Please note that this guide contains a lot of info on the 5X as well, so please make sure you don't use the 5X settings by accident.
(If you own a Nexus 5X or 6P and you are too lazy to read the philosophy of this technique, head on down to the 2nd post and pop those values into your kernel manager and be happy. If you own a different device, please read this post in full.)
The Introduction
I'm about to tell you how to get buttery smooth, lag free performance with insanely good battery life, using an old school governor featured in practically every kernel... This tweak is applicable to every phone with any ROM or kernel--stock or custom--that provides the Interactive Governor. :good:
Yeah, yeah... everyone promises good battery with great performance, but who actually delivers? Maybe it isn't as smooth as you want, or maybe it requires something your kernel or ROM don't support. Or maybe the battery life promises just aren't what you expected. There's always some awful compromise. Not here!
This isn't a guide to get 36 hour battery life... provided you never use your phone. That's deep sleep optimization, which is lovely and all, but what good is the phone if you can never use it?! And with the new Marshmallow Doze feature, this strategy is becoming a think of the past. What I'm talking about is 7-14 hour screen on, actual hands-on usage times! Without compromising anything, you can get 7-8 hour screen on usage with regular, no-compromise usage habits: daytime visible screen brightness, both radios on, sync on, network location on, all the regular usage features, the whole kit and kaboodle... all smooth as a baby's butt and snappy as a Slim Jim! (Up to 14+ hours if you can stand minimum brightness and WiFi-only with a custom ROM and other stuff turned off! And this is with stock voltages and full frequency range--you'll likely get even more if you choose to optimize those as well!)
However, it should be noted that this does not apply to gaming, heavy camera use, etc. Anything that is an automatic battery killer in and of itself. There's nothing that can be done about anything that forces the phone to utilize its maximum resources all the time. But you should know that by now. Further, this guide is about optimizing the CPU as much as possible. It does not cover things like eliminating wakelocks so your phone sleeps well, removing unnecessary and battery draining stock apps, keeping your screen brightness down*, and all that stuff that's been covered in other posts ad infinitum. Those optimizations are up to you.
*At least on the Nexus 5X, you shouldn't be turning your screen brightness above about 60%. It should be more than viewable in sunlight at that brightness, and keep in mind that the brightness power requirements increase exponentially, so a 100% bright LCD screen will use about 3.5-4.5x more power than a 60% bright screen. I don't see that fact brought up often, so I thought I'd mention it here.
After a bit of tweaking and experimenting, I developed some settings that provide absolutely incredible battery life, buttery smooth performance, and a lag free experience. And you don't need a fancy governor, or a custom kernel, custom clock rates, or even a Nexus 5X. This will work on any ROOTed phone with the Interactive governor!
So, after writing a (nearly identical) guide for the EvoLTE folks over a year ago, I'm now back to update this information to provide strategies for multi-CPU devices, as well as specific settings for the Nexus 5X you can use right away.
Enough long winded preamble! Let's get down to...
The Nitty Gritty
Before I lay out all the settings so you can blindly enter them into your governor control, I should to explain some of the principals I employed to get the results I did. The primary thing to understand before I do is: little might you know, the settings in the Interactive governor can be tweaked on a clock range basis. That is to say, you can finely control how the governor responds at a variety of clock rates, thus better dictating how it should operate under various loads. This is integral to the configuration, because it means the difference between jumping from the slowest speed to the highest speed under load and sustaining lower clock speeds for tasks that don't really require higher clock speeds.
By default, the Interactive governor will jump from lowest speed to a "nominal" speed under load, and then scale up from that speed as load is sustained. That is lovely, but still too twitchy to provide serious efficiency and power savings. It spends most of its time at 2 or 3 clock speeds and barely hits other clock speeds that are ideal for other tasks or usage patterns.
Instead, what we want to do is configure it to handle different types of loads in different ways. A load suited for scrolling through a webpage is not the same as a load suited for downloading/processing streaming video is not the same as a load suited for snappy loading of an app is not the same as a load suited for high performance gaming. Every kind of load has different tolerances at which their minimal speed is indistinguishable from their maximal speed.
To understand what's best under a variety of tasks, we have to identify two types of load profiles: nominal clock rates and efficient clock rates.
Nominal Clock Rates
Nominal clock rates are the minimum CPU clock rates that perform a given task smoothly and without stuttering or lag. To find the nominal clock rate for a given task, turn on only the first CPU using the Performance governor and turn them both down incrementally until you find the minimum clock rate that works best for what you're trying to do, without introducing hiccups. (If you have a CPU or kernel that hotplugs individual cores, multiply that clock speed by your number of cores.) Keep the 2nd CPU on the Powersave governor with the lowest frequency your kernel supports. (Or turn it off completely if hotplugging allows.)
(Note: If your device supports per-core hotplugging, you might be better off using the old guide to determine your nominal clock rates. The Nexus 5X and all current kernels only support hotplugging entire CPUs, so your results may vary if you use any other device.)
For example, on my Nexus 5X, scrolling (not loading, simply scrolling) through a large webpage smoothly will occur when the first CPU clock rates are no less than 460Mhz. (This is on mine without background tasks taking any CPU. Yours may be different depending on services running, the browser you use, your ROM, kernel, etc.) Thus, the nominal clock rate for scrolling a webpage on my Nexus 5X is 460Mhz.
Efficient Clock Rates
Efficient clock rates are CPU clock rates that are unique in that they are the most optimal frequency given the range of voltage requirements. If you map out the frequency jump and the voltage requirement jump between each of the available clock rates, you will find that occasionally the voltage requirement will jump significantly without the frequency jumping proportionally to the previous differentials. For example, using stock voltages, the EvoLTE's msm8960 chipset clock/voltage ratios jump significantly higher from 702Mhz to 810Mhz than the ratios from 594Mhz to 702Mhz.
Because I cannot find the stock voltages of the Nexus 5X clock speeds, this section is INCOMPLETE! If you know the voltages, please post and I can update this guide to include the 5X's Efficient Clock Rates.
Clock Rate Biases
Using the information provided above, figure out both your nominal clock rates for the tasks you perform most often and your efficient clock rates depending on your kernel/custom voltage settings. For me, since I cannot determine the efficient clock rates, I use the nominal clock rates listed above. For the tasks I generally perform on my phone, my nominal clock rates are as follows:
Idle - 384Mhz
Page Scrolling - 600Mhz
Video - 787Mhz
App Loading - 960Mhz
High Load Processing - 1440Mhz
(Note that you must calculate the values that are optimal for your phone for best battery and performance! Each phone is different because of the ROM, kernel, background tasks, etc!)
With this done, you will want to start the fine tuning phase! Correlate the efficient clock rates with their closest nominal clock rates, similar to below:
(This section of the guide is INCOMPLETE because I do not know the clock rate voltages for the Nexus 5X. If you know these, please post in the comments and I will update the guide!)
Idle - ???Mhz efficient / 384Mhz nominal
Page Scrolling - ???Mhz efficient / 600Mhz nominal
Video - ???Mhz efficient / 787Mhz nominal
App Loading - ???Mhz efficient / 960Mhz nominal
High Load - ???Mhz efficient / 1440Mhz nominal
Keep these handy, as they're going to be necessary for...
The Set Up
Now that we know what are the most efficient nominal clock rates we want to focus on and what the most optimal are for what we want to do, we will start low and scale up as necessary. It's always better to begin with underperforming and tweak the settings upward until we're satisfied with the performance of our target tasks.
In its default state, the Interactive governor has a hair trigger that will raise and lower the clock rates, which means it spends too much time at unnecessary clock speeds, wasting power, and scales down too quickly, leading to stuttering performance. We will take advantage of a seldom used feature of the Interactive governor. Specifically, that with which it determines when it is okay to scale up to each higher clock rate, on a frequency by frequency basis.
We have two primary goals: respond as quickly as possible to each load request for a lag free experience and exceed the desired clock rate for a given task as little as possible. To do this, we will instruct the Interactive governor to trigger certain clock rates in different ways depending on our expected load.
I won't explain all of the settings of the Interactive governor--there are plenty of summaries all around. (Go search now if you don't know what any of the settings for Interactive governor do. I'll wait here.) However, I will explain an incredibly powerful feature of the Interactive governor that is rarely included in those summaries: multiple frequency adjustments.
The above_highspeed_delay setting, for example, defines how long the governor should wait before escalating the clock rate beyond what's set in highspeed_freq. However, you can define multiple different delays that the governor should use for any specified frequency.
For example, we want the above_highspeed_delay as low as possible to get the CPU out of the idle state as quickly as possible when a significant load is applied. However, we don't want it to jump immediately to the fastest clock rate once it's gotten out of idle, as that may be overkill for the current task. Our target trigger (which you will later adjust to suit your system and usage profile), will begin at 20000μs. That means 20,000μs (or 20ms) after our idle max load has been reached, we want to assume idle has been broken and we want to perform an actual task. (We want this value as low as possible without false positives, because it is one of a few factors that determine how snappy and lag free the CPU's response is.)
But at this point we're not ready to take on a full processing load. We may just be briefly scrolling a webpage and don't need the full power of the CPU now that we've allowed it to break out of idle. So we need it to reach a particular frequency and then hold it there again until we're sure the load is justified before we allow it to push the frequency even higher. To do that, rather than just setting
above_highspeed_delay - 20000
we will instead use the format "frequency:delay" to set
above_highspeed_delay - 20000 460000:60000 600000:20000
"Waaaait... What does that do?!"
This tells the Interactive governor to hold out 20ms after our target load when it's at our highspeed_freq (which we're actually using as our idle frequency--not a burst frequency as originally intended), but then it tells the governor to hold for 60ms after it's reached 460Mhz. Once it has exceeded 460Mhz, it then has free reign to scale up without limitation. (This will be optimized with the target_loads setting in a minute. And if you don't know what I'm talking about when I say "highspeed_freq" then you didn't go search for the basic Interactive governor settings and read about it! Go do that before you read any further, because I will not explain the basics of this governor!)
These settings are among the most important, because they limit the phone's clock rates when you are not interacting with it. If it needs to do something in the background, chances are it does not need to run full throttle! Background and idle tasks should be limited to the lowest reasonable clock rate. Generally speaking, if you're just looking at your phone (to read something, for example), you want the phone to use as little CPU power as possible. This includes checking in with Google to report your location or fetching some pull data or... whatever. Things that you don't need performance for.
So now that we know how to specify different settings for different frequency ranges, let's finish it all up with...
The Money Shot
If you've made it this far, you're ready to put these strategies into play! If you have not read the previous sections, DO NOT COMPLAIN IF THE DEFAULT SETTINGS DON'T PROVIDE WHAT YOU'RE LOOKING FOR!! These settings are templates only and these need to be adjusted for each case based on your system and usage patterns! IF YOU ARE NOT GETTING THE PERFORMANCE OR BATTERY LIFE PROMISED, ***READ THE SECTIONS ABOVE!!!***
With that out of the way... let's rock!
If you are using a Nexus 5X, use the following Interactive governor settings for CPU 1 ("little"–the one with 4 cores) and then tweak with the instructions below:
(If you are using a phone other than a Nexus 5X, you must read the above sections and replace the frequencies with your own efficient clock rates!)
above_highspeed_delay - 20000 460000:60000 600000:20000
boost - 0
boostpulse_duration - 80000
go_highspeed_load - 99
hispeed_freq - 600000
min_sample_time - 30000
target_loads - 98 460000:19 600000:80 672000:12 787000:81 864000:9 960000:69 1248000:95 1440000:95
timer_rate - 20000
timer_slack - 80000
These defaults work fine for me, but I have otherwise optimized my system fully, so they are at the minimal adequate values. If you have background tasks that consume any somewhat significant amount of CPU on a constant basis, you will most likely see awful, stuttery performance and poor battery life! So you must adjust them to suit your system before you see results!!! Anything more than about 15-20% idle CPU use at any given time will negatively affect the results you see without further tweaking!
Optimize Idle Frequency
Now that you've got the base configuration, we need to tweak it so that the CPU stays at your efficient idle frequency (384Mhz in this case) without spontaneously jumping when your phone is actually idle. To do this, open a CPU monitor that displays the current core frequencies (I like CoolTool, but you can use what you like as long as it doesn't significantly impact the CPU use--you're best off using a passive monitor and checking the results after 30-60 seconds of no activity), watch the frequencies and see how often they go above your efficient idle frequency when you're not doing anything at all, and adjust the following:
timer_rate - If your idle frequency is not being exceeded much, adjust this downward in increments of 5000 until it is, then increase it by 5000. If your idle frequency is being exceeded often, adjust this upward in increments of 5000 until your CPU primarily stays at or below your desired idle frequency.
above_highspeed_delay - Only if your timer_rate has matched or exceeded 50000 and still won't stay at or below your desired idle frequency most of the time, set timer_rate to 50000 and adjust the "20000" portion of the value upwards in increments of 5000 until the idle frequency has stabilized.
The lower these two values are, the more snappy/lag free your system will be. So try to get them as low as possible without the idle frequency being exceeded too much, as this inversely affects the snappiness and efficiency of your phone when you're not doing anything. Lower = snappier but uses more CPU when you're not doing anything (such as reading a webpage); higher = less snappy but stays in a power saving state more often reducing CPU use when you're not interacting with the device. These are the most critical in determining your idle power savings, so keep that in mind if you want the most battery life!
Enhance Task Responsiveness
Now use the efficiency and nominal clock rate correlations you made for your master clock rate list in the section above and adjust your frequencies to suit your usage patterns. For example, I had web page scrolling as my 600Mhz rate, so I will open a web page and scroll and see how everything feels. If it feels sluggish, I will increase all the references to "600000" in both above_highspeed_delay and target_loads upwards to the next available clock rate until that task is smooth. What you are looking for is constant poor/sluggish performance when the task you're testing for is using its highest CPU use. If the task becomes sluggish/stuttery as it winds down (such as a scrolling webpage slowing to a stop), we will address that next, so do not take that behavior into consideration as you adjust these values! If the task is smooth until (or after) it slows down, then you have reached your optimal clock rate and can move on.
Find Optimal Loads
Now here's where we get a little math-heavy to determine what the optimal target_load frequencies are for each clock rate. (Might want to bust out a spreadsheet to do the math for you if you're not using a Nexus 5X.)
We want to determine 2 values for every available clock rate: the maximal efficient load and the minimal efficient load. To make this determination, we need to bust out our calculators. (Or spreadsheets!)
For the maximal efficient load, we want to correlate a load value no higher than 90% of a given clock rate before it would be more efficient to jump to the next clock rate–to avoid overwhelming a particular rate while avoiding premature jumps to the next. For this value, we calculate it as:
(clock rate * 0.9) / next highest clock rate
For example, the maximal efficient load for 600Mhz on the Nexus 5X would be caluclated as:
(600000 * 0.9) / 672000 = 80.36% (rounded and normalized: 80)
For the minimal efficient load, we want to correlate a load value at which anything higher would be better served by a higher clock rate. To calculate this:
(1 - next highest clock rate / clock rate) * -1
For example, the minimal efficient load for 600Mhz on the Nexus 5X would be calculated as:
(1 - 672000 / 600000) * -1 = 12.00% (rounded and normalized: 12)
For the Nexus 5X, the maximal efficient loads of CPU 1 are:
384000:75
460000:69
600000:80
672000:76
787000:81
864000:81
960000:69
1248000:78
For the Nexus 5X, the minimal efficient loads of CPU 1 are:
384000:0
460000:19
600000:30
672000:12
787000:17
864000:9
960000:11
1248000:30
1440000:15
For the Nexus 5X, the maximal efficient loads of CPU 2 are:
384000:72
480000:68
633000:74
768000:80
864000:81
960000:69
1248000:83
1344000:84
1440000:84
1536000:84
1632000:86
1689000:83
For the Nexus 5X, the minimal efficient loads of CPU 2 are:
384000:0
480000:25
633000:32
768000:21
864000:13
960000:11
1248000:30
1344000:8
1440000:7
1536000:7
1632000:6
1689000:3
1824000:8
Using Optimal Loads
Now, you might be asking, "Why the heck did I do all this math?! WHAT IS IT GOOD FORRRR????!!!!"
Well, we had put some values into target_loads earlier, but those values weren't arbitrary. See, for all of our nominal clock rates, we want the CPU to hang out on them for as long as possible, provided they're doing the job. For each frequency tagged as our nominal clock rate, we want to use the maximal efficient load in target_loads. For every other frequency, we want to use our minimal efficient load value.
We don't care about those other frequencies. We don't want the CPU to hang out in those states for very long, because it just encourages the device to be reluctant to jump to a higher nominal frequency and causes stuttering. We eliminate the desire for the governor to select those frequencies unless it is absolutely efficient to do so. For all the nominal clock rates, we want the CPU to hang out there... but not for too long! So we set those values to the maximal efficient load, so they can escape to the next nominal frequency before they overwhelm the current frequency.
All said and done, this reduces jitter and lag in the device while providing optimal frequency selection for our day-to-day tasks.
Fix Stuttering
Now that you have adjusted your frequencies for optimal high CPU use in each given task, you may notice some stuttering as the task winds down. (Such as a scrolling webpage slowing to a stop.) If this bothers you, you can tweak this at the expense of some (minor) battery life by adjusting min_sample_time up in increments of 5000 until you are satisfied.
If you have exceeded a value of 100000 for the min_sample_time setting and still are not satisfied, change it back to 40000 and increase (and re-optimize) your idle frequency by one step. This will impact battery life more, but less than if you were to keep increasing the value of min_sample_time.
However, this step should not be necessary if you properly calibrated your maximal and minimal efficient loads!
But What About That 2nd CPU?!
So we've all but ignored the 2nd CPU. The reason? It's a horribly inefficient processor designed for high load tasks that generally don't come into play during normal usage patterns. It's good for gaming and image processing, but not for most moderate tasks a user might employ.
But it is good for one thing that all users do pretty frequently... loading and switching apps.
Fortunately, at least for the Nexus 5X, the system is pretty smart about when to employ the power of this inefficient 2nd CPU. So it's generally kept at bay most of the time. What we want is to configure it to be our burst processor–we want it to come into play spontaneously and quickly during tasks that necessitate immediate high loads, like loading and switching apps. To do this, we will ignore all but 3 frequencies:
384Mhz
1248Mhz
1824Mhz
In this case, we configure it just as we did with CPU 1, but only worry about keeping it idle as much as possible, allow it to jump to 1824Mhz immediately when needed, and encourage it to fall back to 1248Mhz if a sustained load is needed.
These values are ideal for the Nexus 5X, so if you have a different phone, choose the lowest clock rate, highest clock rate, and median efficient clock rate, using the instructions previously.
For the Nexus 5X, we'll jump straight to...
The Money Shot: Part Deux
If you are using a Nexus 5X, use the following Interactive governor settings for CPU 2. ("big"–the one with 2 cores)
(If you are using a phone other than a Nexus 5X, you must read the above sections and replace the frequencies with your own efficient clock rates!)
above_highspeed_delay - 20000
boost - 0
boostpulse_duration - 80000
go_highspeed_load - 99
hispeed_freq - 1824000
min_sample_time - 20000
target_loads - 98 480000:25 633000:32 768000:21 864000:13 960000:11 1248000:95 1344000:8 1440000:7 1536000:7 1632000:6 1689000:3 1824000:95
timer_rate - 20000
timer_slack - 80000
What About Bob Touchboost?
Touchboost is a nifty feature in a lot of kernels (including stock on Nexus 5X) that jumps up the frequency so that you experience minimal lag. However, with all the above settings, touchboost is usally detrimental to the efficiency of the device!
We generally want to keep the CPU on the lowest possible frequency as much as possible, and touchboost interferes with that. Further, because we've set up the maximal and minimal efficient clock rates, as well as burst processing from the 2nd CPU core, we don't need touchboost!
If your kernel allows you to shut it off, try to do so and see if the responsiveness of your device is acceptable. On the Nexus 5X, touchboost adds no perceptual performance gain and only hurts efficiency and battery life. If your kernel doesn't allow you to turn off touchboost, try another one, like the excellent ElementalX.
Your battery life will thank you!
The Conclusion
I have achieved unprecedented performance, smoothness, snappiness, and battery life with the default settings I outlined above. However, your mileage may vary, as every phone, ROM, kernel, installed applications, etc are different. This is a very sensitive governor profile and must be tweaked to just meet the requirements of your system and your usage patterns!
If it is not optimally tuned, performance and battery life will suffer! If you're not seeing buttery smooth, snappy performance, you have not correctly tuned it for your system!! However, if you do have superb performance (and you tweaked the values conservatively and not in large steps), then you will also get the aforementioned battery life.