Silverstone Zeus 850w ST85ZF Quad SLI PSU
Published: 1st August 2006 | Source: Silverstone | Price: |Load Testing
In order for the results from all current and future PSU reviews to remain fair and comparable, Overclock3D uses a custom built Power Supply load stress tester.
The tester will be placing the following loads on each of the ST85ZF's rails:
+3.3v - 20a Load
+5.0v - 20a Load
+12v1 - 10a Load
+12v2 - 10a Load
+12v3 - 10a Load
+12v4 - 10a Load
The results are collected from a Mastech MAS-345 Multimeter which logs its readings via RS232 to a PC.
Efficiency tests are performed by measuring the wattage consumed by the power supply at the mains against the power (in watts) consumed by the OC3D power supply stress tester.
The results may not be as accurate as those produced by professional testing equipment, but will certainly come in handy when comparing several power supplies against each other.
Therefore the efficiency of this power supply can be found by a simple equation: (646 / 786) * 100 that works out to be an efficiency rating of 82.1%.
At present Overclock3D doesn't have the professional equipment required to reliably measure the noise output of devices. However, as a new part of our testing procedure we will be recording the PSU at idle and load so that you can make your own judgments. All recordings are taken at 30cm distance from the unit.
Idle Recording - Download
Load Recording - Download
As previously stated, the ST85ZF utilises a Sanyo Denki San Cooler 80mm fan, which pushes a 42cfm at 34dBA when running at full speed. Thankfully Silverstone have implemented a fan speed controller that adjusts the RPM based on the temperature of the unit.
Under idle conditions the fan speed was significantly throttled. This meant that all that could be heard was the whisper of air moving around the unit. With the ST85ZF installed inside a case, I was unable to hear the unit at all.
When placed under load, the ST85ZF gradually increased the fan speed to counteract the heat. As you can hear from the recording above, the ST85ZF was quite noisy. However, with the ST85ZF installed inside a case, the noise levels were much more reasonable.