Load testing the PSU
Load testing the PSU
Testing a power supply these days is always a bit of a challenge. I mean, without professional load testers it's pretty hard to stress a power supply of this class and actually measure its behavior.
Our first check is with a simple cheapo power supply tester, we monitor voltages quickly and check if all rails are working. All good here.
The test setup
So for our load test here's what we did. We emulate real world usage. We took an Intel P55 based Quad SLI compatible motherboard and armed it with a GeForce GTX 590 card (with two GPUs per card).
We combined the P55 motherboard with a Core i7 870 processor overclocked to 3.8 GHz. The system... well have a look:
These are the components used:
- eVGA P55 Classified SLI motherboard (has fairly high power consumption and an NF200 chip)
- Core i7 870 (overclocked to 3800 GHz) 20x190 BCLK at 1.4 Volts
- GeForce GTX 590 primary (2 GPUs)
- 4 GB Memory DDR3 @ 1520 MHz
- OCZ Vertex 2 SSD x1
Now with a setup like this, many years ago we'd reach 550 Watts power consumption as maximum. But with power supplies getting more and more efficient these days, even that proves to be a harder task to accomplish.
So, above, our graphics card setup. Now on the software side of things it is time to give the PC a decent beating. Remember, our focus remains PSU efficiency.
We now take some other power supplies:
Looking at efficiency is really simple, we apply the same load on several power supplies, from old to new. We look at the powered off status, Windows IDLE status, productivity mode (we stress the CPUs) and during gaming. The lower the wattage, the higher the efficiency.
The best indicator for good efficient power consumption is by looking at the game test. As you can see, the Silent PRO M2 consumes a fair amount of power, but there are Platinum certified products in there. Mind you, a PSU is most efficient at 50% load. Stress it higher or lower and your efficiency will drop a little.
This Silver certified PSU seems to be on par with 88% efficiency standards, good. At productivity mode (CPU used mainly) with 30% load the efficiency dropped down a little though. Again, this PSU is at its best efficiency level when drawing roughly 500 Watts.
Powered off the PSU consumed roughly 1.1 Watts.
With the computer powered on and in absolute IDLE we can notice interesting differences, but they are all real close to eachother.
