Test Equipment & Setup
- CPU: Intel Core i7-8700K
- Motherboard: ASRock Killer SLI
- RAM: 16GB Corsair 3733MHz
- GPU: EVGA GTX 1080 Ti SC2 ICX
- GPU: EVGA GTX 1080 Ti FTW3 ICX
- SSD: Kingston KC1000 480GB
- PSU: SilverStone SST-ST1500-GS
- Fans 3x Corsair ML120 Pro
- Cooling: EVGA CLC Cooling 240mm
- OS: Windows 10 Professional X64
We measure the voltage from the wall using a KillAWatt voltage measuring device then dissect each line with a multimeter. To jump-start the power supply you jump pins on the 24 pin power connector specifically 15 and 16 the green and black wires. The Jumpstart method is to test a PSU out of the box before connecting it too expensive hardware. This test can also be done with a dedicated PSU tester that's fairly inexpensive.
Then there's the tricky part where your machine is hooked to the PSU and you stress different components to achieve the voltage you want to test. We stress the CPU at stock speed, then OC the CPU to the maximum stable speed, read the voltage from the wall and made note of it, then the black probe goes into any black wire from the back of the 24 pin mainboard connector. The black wires are grounds and we can use the same one on all the tests. Then as we want to pull more voltage we can stress a single 1080 Ti and record the voltage and rerun the 12V test. We add a second 1080 Ti and stress both in SLI and finally we OC the SLI array and stress both with the CPU overclocked to the max and both 1080 Ti maxed out. That's about as much voltage as you can pull without a synthetic load line tester.
You don't just test the wires willy nilly, of course, there's a set wire for each test and here's a schematic of what wires do what when it comes to PSU testing.
Most PSU run a + or - 5% and consider that nominal, SilverStone beats that and the measurements on the SST-ST1500-GS are + or - 3% and SilverStone guarantees that so you can bet the manufacturing and testing on these units are stringent.