When it comes to testing a power supply, there are two courses to travel. One takes you down a path using a device to stress out the PSU and provide data regarding the power levels across all three rails. The second, and the one I make use of, utilizes an actual test system to give a more real-world account of what the power supply is capable of. While both methods have their merits, I prefer to use an actual computer to more closely resemble the manner of use that you, the potential customer, will put the product through.
That said, let's take a quick look at the test system. At the request of readers, I have beefed up the system to put a more realistic strain on the power supply.
Gigabyte 965P-DS4 motherboard (Supplied by Gigabyte)
Intel Core 2 Duo E6600 processor
2x 1024MB Corsair XMS2-8500-C5 memory (Supplied by Corsair)
GeCube X1900XTX graphics (Supplied by GeCube)
Sapphire X1900XT graphics (Supplied by Sapphire)
Western Digital 250GB SATA hard drive
2x Western Digital 160GB SATA hard drives
Western Digital 80GB hard drive
Sony 52x CD-ROM optical drive
Samsung 16x DVD-R optical drive
2x 120mm fans
4x 80mm fans
Testing will consist of checking the power levels across all three rails at idle and again while the system is under stress. This should give us a good look at the capabilities of the power supply being tested.
Overall we have a very steady power supply on our hands. All voltage rails showed a tight level of power being put out regardless of system state. With both the 12v and 3.3v rails showing higher than rated values, there will be more then enough juice to take care of business. Since the 5v rail only shows a .01v and .02v drop from rated specs, there are no issues here.