Intel Core i5-2500K Sandy Bridge
Corsair Hydro H70 Liquid CPU Cooler
MSI R6850 Cyclone PE / OC VGA
Corsair 2x 2GB XMS3 DDR3
Seagate 400GB HDD
OCZ ZS Series 750W PSU
Corsair Obsidian 650D Chassis
Windows 7 Home Premium 64-bit
The power supply looks at home in my test rig although I do wish OCZ had went with a thicker grade of mesh that would help hide the color of the wires. Otherwise I didn't run into any issues during installation. I was able to tuck unused cables behind the motherboard tray and under the hard drive cage. The CPU power cable had plenty of length and I could have probably run it behind the motherboard as well.
Using a Kill-a-Watt meter, I measured the power usage of the system at the outlet, during both idle and load. To generate the load I used OCCT's power supply test utility, which stresses both the CPU and GPU up to 100%. I also ran Prime 95 for good measure. Additionally I disabled all power saving features in the BIOS. At idle, only 100 watts are being used. A full system load only generates a draw of 299 watts, or roughly 40% of what this PSU is capable of.
I think a lot of people tend to overestimate just how much power a typical high-end system draws. This is a respectable system with a nice midrange graphics card that doesn't even draw 300 watts of power under full load. As such, it really only makes sense to own a high wattage power supply if you have some serious hardware under the hood like multiple high-end video cards and / or a power sucking Socket 1366 CPU.
The 80 Plus verification test report reveals 84.98% / 86.86% / 83.70% efficiency at 20% / 50% / 100% load with an average efficiency of 85.18%.
With a digital multimeter, I also took voltage readings at the back of various connectors under idle and load conditions. The +5V rail was the most stable since it didn't move going from idle to load. The +3.3V rail was also very stable. The biggest fluctuation came at the PCIe connector for the video card, which dropped .09v under full load.
Unfortunately these are the only tests we are capable of conducting at this time. We do not have access to expensive power supply testing equipment nor would we expect most of our readers to understand the detailed findings that such equipment outputs. If you are an electrical engineer or a hardcore PSU enthusiast, I would suggest you check out some other more detailed reviews on this unit or any other before making a purchasing decision.
Let's move on and wrap things up with some final thoughts and a conclusion.