Antec Signature 650W Power Supply

Temperatures, Fan Speed, and Acoustics

Because of the low height of the installed heatsinks, they have a rather small volume. This means they hotter if they're not cooled correctly. The design of the Signature series is a bit different from other power supplies, so we can't directly compare the heatsink temperatures with other topologies. Regardless, larger heatsinks have a better chance to dissipate the heat. It's important to look at the difference between the heatsink temperatures and the exhausted air temperature, since this indicates whether the heatsinks are actually dissipating into the airflow effectively. The closer exhaust temperatures are to the heatsink temperatures, the better the heat dissipation. The Signature seems to have slight problems with dissipation, but it's nothing to worry about since the heatsinks only reached up to 80°C.

We have to admit that we haven't seen such a rapid increase in fan speed in such a short time before. The Signature stay very quiet up to 50% load, which is around 325W of power draw. After that, the fan quickly begins to spin much faster and reaches more than 3000 RPM at full load. That certainly isn't quiet anymore, with fan speeds similar to the PC Power & Cooling Turbo Cool 1200W.

As expected, the noise level increase matches the fan speed increase. The power supply is almost inaudible at only 17dB(A) all the way up to 350W of load, but then it gets louder fast and reaches its 33dB(A) zenith at full load and 10% overload. Of course, here we need to mention that with the provided connectors, users will have a difficult time reaching full load.