Corsair TX750W Power Supply

Temperatures, Fan Speed, and Acoustics

We really don't like CWT's heatsink design on their current power supplies, and the temperature readings show that our feelings are not without merit. The third heatsink reaches almost 80°C, which is quite hot for a modern power supply -- and this is running in a comfortable 25°C environment; imagine how hot the power supply would get with higher ambient temperatures. The result of higher temperatures is that the fan will need to run at maximum speed all the time. The exhaust temperature does stay relatively close to that of the first two heatsinks, which is good; that means they are doing a good job of transferring heat into the airflow and getting the heat out of the power supply. The problem is that the third heatsink has a temperature 20°C higher than the others.

The fan spins at ~1100 RPM at lower loads of up to 20%. The fan begins spinning much faster at 50% load, even though temperatures are still reasonable. The first two heatsinks are only 10°C higher, so the dramatic ramp in fan speed shouldn't be necessary yet, but the fan is already spinning at around 1600 RPM. Maximum fan speed is reached at ~80% load, and it appears fan speed is being regulated by the temperature of the third heatsink as we can see above that the temperature is quite a bit higher.

The TX750W fan is not silent, and a moderate increase in fan speed results in a dramatic increase in noise levels. At minimal load, the power supply generates 21dB(A) of noise, which isn't terrible but it isn't great either -- you wouldn't normally notice the power supply when it's installed in a system at low loads. At 50% load the volume increases 7dB(A), which definitely becomes audible. You definitely do not want to run at anything near maximum load, however, as 80% load results in 39dB(A) and 100% load is 40dB(A)! If you are interested in silence (or even near silence), there are without doubt better power supplies.