I've been playing with power supplies for quite a while now and I guess in my old age, I like to sometimes make things interesting. My normal method of testing a PSU was to get the system up and running, get a burning session on a CD-RW running in the background, then cranking up something along the lines of Quake 4 and run a long-winded demo. Once everything is cranked up, I'll measure the voltage levels along the power rails to see how close they remain to specifications. The thought behind this method of testing is to see if the power supply can maintain acceptable power levels while under stress.
While I will continue to use this methodology, I also decided to compare these results with the power levels at system idle just to see how much the unit drops off while the system is under a load. This should give us a little more in depth picture of what the PSU in question is capable of. After all, with power supplies becoming a very important component in modern computers, it pays to know ahead of time what works and what doesn't.
But before we dig into the multimeter readings, lets take a quick look at the test system being used:
DFI LANParty UT nF4 Ultra-D motherboard (nVidia nForce4 Ultra chipset)
AMD Athlon FX-53 processor (Supplied by Newegg.com)
2x 512MB Mushkin "Redline" PC3200 memory (Supplied by Mushkin)
GeCube X1900XTX graphics card (Supplied by GeCube)
Four case fans + Thermaltake CPU cooler using 80mm x 38mm high performance fan
All right then... the system is running and the tasks are chugging along. The processor is at default speed and voltage is set to 1.5v. The memory is running at 2.9v and all other levels are set to default. The motherboard is an absolute power hog and the video card has sent many lesser power supplies to an early grave. Let's see what this thing can do!
For those running newer processors, the main concern will be the 12v rail. For those still running something along the lines of a Socket A Athlon, the 5v rail will be of higher importance. It only takes a quick glance above, however, to see that it won't matter.
The OCZ GameXStream 600 managed to put up very solid numbers on all three voltage rails. This is especially interesting considering that the DFI mainboard being used requires both a 4-pin Molex and a FDD connection to be made from the power supply. This motherboard literally drains the life out of many lower-end models on the market but the OCZ didn't even flinch. This is excellent news for those who are looking at building that awe inspiring monster rig to take to your next LAN.
One item of note was the amount of fluctuation in this unit. While the levels never came down to under full factory specs, I saw a regular fluctuation of roughly .03 - .06v along the 12v and 5v rails. While I was a little concerned about this at first, no amount of torture was able to cause even the smallest amount of system instability, so I'll have to write it off as a trivial fact.