XFX 850W Black Edition Modular Power Supply Review

We will start with testing the 3.3V rail, which doesn’t cater for many of the computer’s components in this day and age. They are generally left for higher voltage rails, mainly the 12V rail.

The results of testing the 3.3V rail were pleasing, giving stable results at 3.38v on idle and 3.36 at load. We generally have a certain range to which satisfies our need for stability, and the 3.3V rail falls well within it, demonstrating less than 1% variation.

Next up for the test was the 5V rail, which being very similar to the 3.3V, doesn’t power the higher end components of a computer system but still important none the less.

The 5V rail gave results of 5.11v on idle and 5.09 on load which give a variation below 1%. Once again showing how stable this unit is. From previous tests we generally see that putting the 5V rail under some strain will induce under-volting (as we did with the 650 and 750watt versions from the same manufacturer) but this 850watt seems to be something a little bit more special.

The last test to do was on the all-important 12V rail. Some brands opt for multiple 12V rails to distribute the power evenly, XFX have plumped for a single high-power 12V rail to power the most power hungry components of the system.

This unit can’t be faulted with stable results again, giving 12.10V on idle and a staggering close 12.04V at load (0.5% difference!) giving us the feeling that this unit will be perfect for even the most extreme gaming and overclocking rigs.