Antec Signature 850W PSU

Results

The results are absolutely fantastic. Look at the voltages - barely a flicker out of spec regardless of load! The efficiency is also super high, and while "lower" than the Cooler Master Ultimate UCP 900W, it's still exceedingly high. At a consistent 87-88 percent efficiency over 50 percent load it's certainly better than most PSUs we've seen to date, in fact, it's only rated Bronze not Silver in the 80 Plus program because of its 20 percent load efficiency that drops down to just under 84 percent. This is higher in our testing than the UCP 900 that could only manage a percent lower.

For the most part the efficiency is also upwards of 98 percent which is very good, although this drops slightly to just less than 95 percent at 20 percent load. Again though, this is better than the UCP 900 which was a lowly 89 percent.

At 20 and 50 percent load the unit is very cool and is very quiet indeed - barely noticeable in fact. Just a slight fan whirr can heard out the back, but then only if really listen. At 75 percent load the unit warms up a bit, as expected, and the fan gets a little louder but still quiet and completely unintrusive.

When we hit 100 percent load for either 3.3V/5V weighting or the 12V rails, the fan speed increases quite substantially, as does the air and case temperature to something quite warm - certainly on par with other units, despite the far smaller exhaust surface area. It's nowhere near our experiences with the dual PCB Etasis we reviewed last year that was criminally hot.

The fan noise is certainly tolerable at 100 percent load, but it is quite noticeable, although with a couple of graphics cards, several hard drives and CPU cooling all fired up we'd highly doubt you'd hear it over a system needing 850W of power. It's certainly quieter than PC Power & Cooling TurboCools we've seen (albeit many moons ago, not more recently) and its a few notes quieter than the 750W Silencers we use in the labs.