Q. What is Voltage Drop? (Vdrop for short)
A. Voltage drop describes how the supplied energy of a voltage source is reduced as electric current moves through the passive elements (elements that do not supply voltage) of an electrical circuit. Voltage drops across internal resistances of the source, across conductors, across contacts, and across connectors are undesired; supplied energy is lost (dissipated). Voltage drops across loads and across other active circuit elements are desired; supplied energy performs useful work.

For example, an electric space heater may have a resistance of ten ohms, and the wires which supply it may have a resistance of 0.2 ohms, about 2% of the total circuit resistance. This means that approximately 2% of the supplied voltage is lost in the wire itself. Excessive voltage drop may result in unsatisfactory operation of, and damage to, electrical and electronic equipment.

National and local electrical codes may set guidelines for the maximum voltage drop allowed in electrical wiring, to ensure efficiency of distribution and proper operation of electrical equipment. The maximum permitted voltage drop varies from one country to another.[1] In electronic design and power transmission, various techniques are employed to compensate for the effect of voltage drop on long circuits or where voltage levels must be accurately maintained. The simplest way to reduce voltage drop is to increase the diameter of the conductor between the source and the load, which lowers the overall resistance. In power distribution systems, a given amount of power can be transmitted with less voltage drop if a higher voltage is used. More sophisticated techniques use active elements to compensate for the undesired voltage drop.

Q. Why would I want to check my voltage drop?
A. Well, the purpose of this is to check how much voltage your psu is dropping when the components are being fully pushed to their maximum capabilities, as in putting maximum load, therefore pushing the power supply to it's limits, depending on he PSU and the components you have. The data you people are going to provide (along with mine) can serve the purpose of a benchmark for various power supplies, even though the data we will gather may not be that accurate.

Q. So what do I have to do?
A. Well, firstly you are going to need a software that pulls data like voltages and temperatures directly from the bios. (This description of mine may not be accurate so feel free to correct me if I am wrong)

What you are going to need is the software utility that comes bundled with your motherboard that usually lets you overclock or monitor and control stuff like fan RPM, voltages, clocks, and etc. from within windows. The reason why I am opting for the bundled software is that, while the software reading may not be the most accurate, usually these software provide the data pulled directly from the motherboard's sensors.

Here are links to a couple of software that are bundled with the well known motherboard manufacturers that will allow users to monitor what we need.

Gigabyte motherboards: Easy Tune

Asus motherboards: PC Probe

ASRock motherboards: ASRock Extreme Tuner

MSI motherboards: Control Center

*Note: Check your manufacturer's website for details on software compatibility, since there are different versions of these software that are built specifically for specific hardware, e.g. the intel version of Easy Tune will not work on AMD hardware, and vice versa. I recommend that you download the latest version to avoid instabilities like BSOD and make sure the software is run with administrator rights. As I couldn't find proper links for a download to some of the software, I have left it to the hands of the participants (that means YOU) to download the proper software corresponding to your motherboard.

Procedures for the test: Start the corresponding software for your motherboard, and monitor the +12V ratings when the system is idle. Then run Furmark in windowed mode, and note the voltages, and if you want to get extreme, grab Prime95 or Intel Burn Test while Furmark's running, for a complete assessment. You can also use MSI Kombustor, OCCT, Linpack or whatever you may prefer. Even running a game that makes good use of the hardware in windowed mode will do nicely.

Procedures for submission: Simple enough. A screenshot of the corresponding software for you motherboard while in idle state, and a screenshot of it in full load, and also mention the make and model of the PSU with a link to the manufacturer's website with the usage period should do nicely.

My Submission:

PSU Name: Cooler Master Thunder 700W



While Idle

Prime95 (65W approximately) stress test along with HD 7850 running Furmark

Intel Burn Test (Only CPU is stressed, 86W average)


Attached Thumbnails




Show more