Results, performance, noise
We added Enermax's well-received REVOLUTION 85+ and Cooler
Master's UCP 900W Ultimate PSUs as comparisons. Full reviews on them
coming soon.
| Readings under load | Power & efficiency | Temperatures | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PSU | +12V1 | +12V2 | +12V3 | +12V4 | +12V5 | +12V6 | +5V | +3.3V | -12V | +5VSB | Input power | Ideal output | Actual output | Efficiency | Ambient temp. | PSU temp (start) | PSU temp finish (case and internal) | Temp. delta | |
| Corsair HX850 | Voltage | 12 | N/A | N/A | N/A | N/A | N/A | 5.04 | 3.245 | -12.1 | 5.015 | 933 | 851.1 | 851.08 | 91.2% | 27.5 | 28 | 37.4 (42.5) | 9.4 |
| Current | 65 | N/A | N/A | N/A | N/A | N/A | |||||||||||||
| Cooler Master UCP 900 Ultimate | Voltage | 11.96 | 11.882 |
12.04 | 12.047 | N/A | N/A | 4.98 | 3.267 | -12 | 4.845 | 1011 | 901.75 | 900.47 | 89.1% | 28.3 | 26.5 | 39.9 (58) | 13.4 |
| Current | 18 | 14 | 18.75 | 18.75 | N/A | N/A | |||||||||||||
| Enermax REVOLUTION 85+ | Voltage | 12.105 | 12.027 | 12.04 | 12.123 | 11.98 | 11.945 | 5 | 3.247 | -11.57 | 4.935 | 927 | 852.1 |
852.03 | 91.9% | 28 | 28.6 | N/A | N/A |
| Current | 7 | 6.5 | 12.5 | 2 | 25 | 12.5 | |||||||||||||
Performance
The main wattage-eating components all pull from the 12V line(s). Corsair's HX850 supplies 65A for a total 12V load of 780W and it posts a 90 per cent-plus efficiency rating at full load. That's healthy on all fronts. The comparison Cooler Master is rated a little higher, at 900W, and provides a combined 69.5A (834W) that's split over four rails. The six-rail Enermax REVOLUTION 85+ also produces excellent efficiency results via its combined 65.5A (786W) loading, where each rail can be loaded up to 30A, although, of course, not all concurrently.Indeed, there's little to split the three supplies based on load measurements. We also measured how hot the casing (via thermistor) and internals (via infra-red gun) became after a 40-minute load run. The Enermax REVOLUTION 85+'s results aren't included as the casing insulates against accurate temperature measurement.
We don't think it matters if a PSU has a multi-rail 12V setup if it can spit out plenty of amps on each line. Both the Cooler Master UCP 900 and Enermax REVOLUTION 85+ do so, intimating that Corsair doesn't have an advantage here unless you want to run some mega-power-hungry TEC that will draw amps like no tomorrow.
The single 12V rail was very stable on the Corsair and Enermax supplies but undervolted just a touch on the Cooler Master. Ripple - or lack thereof - is good on supplies and well within tolerances. The Corsair HX850's performance is better than the Cooler Master but just shy of the Enermax in this regard.
Noise
It's rare that you would run the PSU at full load continuously. The
Corsair HX850's fan spins slow enough to be masked by system noise
until the load hits 525W or so. After that, there's a slight increase
as the fan keeps the PSU cool with greater and greater load imposed
upon, and whilst noticeable at the full 850W its pitch isn't
particularly annoying. The HX850W matches the Cooler Master here but is
pipped to the post here by the REVOLUTION 85+, which was a touch
quieter at full load.
