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. I have continued to beef up the system to put a more realistic strain on the power supply.
MSI X48C Platinum motherboard (Supplied by MSI)
Intel Core 2 Duo E6600 processor
2x 1024MB Corsair XMS2-8500-C5 memory (Supplied by Corsair)
2x Sapphire X2900XT graphics boards in CrossfireX configuration (Supplied by Sapphire)
2x Western Digital 250GB SATA hard drive
Western Digital 160GB SATA hard drives
Sony 52x CD-ROM optical drive
Samsung 16x DVD-R optical drive
1x 200mm fan
4x 120mm 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. Each of the X2900XT boards is capable of pulling close to 250 watts of power. 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.
While we have seen a lot of nice features and goodies that come with the Tagan BZ1300 power supply, the primary concern still comes down to numbers. How much power is delivered to the rails when it is running? How much drop do we see when we stress the system? Are there large amounts of fluctuation in the voltage rails during operation? All of these questions are what make us go out and buy a power supply.
After testing was complete, I can say without reservation that if you have a need for massive amounts of power, the BZ1300 is going to be one of your better choices. All voltage levels are solid, the drop between idle and load is minimal (even with a dual graphics setup), and the only fluctuations of power I saw during all phases of testing consisted of a 0.01v flutter on the 12v rail at idle. This monster easily handles a dual X2900XT video array and doesn't even stutter. Granted, not a lot of us really have a need for this much juice, but if you do, it delivers... Period!