The cross-load diagram looks good: the +5V and +3.3V voltages deflect by no more than 2% from the nominal value at any permissible load while the +12V only deflects by 3-4% (to remind you, a deflection of 5% is considered allowable) at nearly maximum loads.
The output voltage ripple is low at max load, barely reaching 50 millivolts even on the +12V rail, the allowable maximum being 120 millivolts.
The PSU employs a Protechnic Electric MGT8012UB-R25 fan. The maker’s website only reveals that the letter U stands for Ultra High Speed. The latter could be deduced from its consumption current of 0.66A, which is very high for an 80mm fan.
Such powerful fans are usually designed with fewer blades (even with three blades only) and in thicker cases (80x80x38mm instead of 80x80x25mm), but this one is designed like an ordinary 7-blade 80x80x25mm fan. This sounds somewhat disturbing even before you turn the PSU on. Seven blades on an 8W motor can hardly be quiet.
And really, the PSU could keep the fan speed at 3200rpm until a load of 500W (this was not quiet, yet acceptable), but then the speed grew up to a fantastic 5500rpm and the sound of the OCZ1000PXS could be easily distinguished against the roar of the four fans our testbed was equipped with (which were two powerful 120x120x38mm fans with a rated speed of 2800rpm and two 80x80x25mm fans at 3000rpm). And I can’t even say the PSU ensures exceptional cooling. The air temperature grew by about 12°C in it at the maximum, which is rather a typical value. It seems that most of the fan’s power is spent pushing the necessary amount of air through the densely packed components of the PSU that produce a considerable resistance to the air flow.
The PSU is just a little less efficient than the above-described Cooler Master Real Power Pro, confidently fitting into the 80 Plus requirements and notching 86% at one point (at a load of 470W).
Summing it up, the OCZ ProXStream 1000W is good in everything except its noise. With its superb quality of manufacture, excellent voltage stability, low voltage ripple, and standard ATX form-factor, this power supply is, unfortunately, not suitable for home use. It will make a perfect PSU for a server that is located in a dedicated room where nobody would care about its noise. Alas, replacing the fan with a quieter one is not possible. The use of such a powerful fan is necessitated by the PSU’s high component density.
Note that OCZ Technologies has a 1000W GameXStream model with a 120mm fan. This model has standard dimensions of 150x86x140mm, too, but I can’t tell you anything about its noise until we have it in our labs. These two models are surely designed in different ways: the ProXStream just wouldn’t accommodate a 120mm fan.