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
While this isn't a Quad-GPU setup, we are certainly in the realm of having a system that is going to put a significant power drain on any power supply. 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.
Whether the test system was at idle or under stress, the Thermaltake Toughpower 1200 was still producing over factory spec voltage levels to all rails. Even when running a dual X1900 graphics system with a selection of potent 3D games, the power levels never dipped down any lower than is shown in the graph. Granted, I expected to see this level of performance from a 1200 watt beast, but it is good to know that the power you get to your system will be strong and rock solid.