Corsair HX850 V2 Power Supply Review
Simulated Load Results (Graphs)
Because I understand that not everyone enjoys getting a headache from trying to read the tabulated results over on page 4, this page is dedicated to some pretty looking graphs that sum up the majority of the results in an easily digestible format.
When viewing the graphs you need to bear in mind that the highest and lowest values on the Y-axis (voltage) represent the maximum and minimum voltages allowed by ATX specifications. If the results should fall outside the graph at any time, then that's an instant FAIL. However, merely staying inside these boundaries does not necessarily indicate a good PSU. In order to display truly great voltage regulation, a PSU must stick as closely as possible to the thick white horizontal line (ideal voltage) as possible.
You will also notice that the graph is split into three sections as depicted by the Green, Amber and Red backgrounds. These indicate normal usage (green), heavily uneven load distribution (amber) and overloading of the PSU (red). For the most part all we need to worry about is how it performs in the green section, but good performance in the other sections will undoubtedly earn the PSU extra brownie points.
Starting with the +3.3v rail, the HX850 offers a very gentle downward gradient across the normal load results (T1-T4) indicating excellent stability. Furthermore, the near-Idle results in T1 come out at 3.34v showing that Corsair have not attempted the age-old trick of over-volting the output at idle to make the full load results seem more favorable. Both of the cross-load voltages are pretty much perfect as well - the first time I've ever seen such a result in any PSU tested on OC3D.
The +5.5v rail tells a similar story with not much of a dip in voltage from idle to full load under the normal tests. The only real difference is that the idle voltage starts a little higher at 5.05v, bringing the rest of the results up a tad and placing the voltage output during test 3 at exactly 5.00v. Once again, the cross-load results are easily the best I've ever seen with almost perfect voltage outputs.
As I've come to expect form Corsair PSU's, the +12v rail results during normal load tests are so flat that I could park my car on them with the hand-brake off. Manufacturing a PSU that drops only 0.16v from idle up to 852w is no mean feat, and it's good to see that Corsair haven't let their standards slip over the years with the release of their new line-up. Best of all though is the TMax result that drops to only 11.80v when running at a whopping 1081w - 231w over spec.
Finally we come to the tree hugging and money saving bit. Corsair have had the HX850 certified as an 80Plus Gold unit, which essentially means it must be 87% efficient at 149.6w / 850w loads, and 90% efficient at 425w. As we can see, that is absolutely no problem for the HX with just over 91% efficiency or greater in all of the standard tests. Only when we apply the extreme cross loads does the % levels drop but this is not part of the ATX specifications. Its worth noting by our tests this would pass the levels needed for a platinum rated efficiency!
If you're interested in how the HX performed under the oscilloscope. Read on....