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.
When I began to run the system at full load, I noted a little drop in the 12v rail, but this was to be expected. After all, any graphics subsystem that has the potential of drawing close to 500 watts of power is going to put some stress on the rail. That drop, however, was minimal. During this phase of testing I noted a 0.01v fluctuation on the 12v rail, but this is a very small ripple and will have no effect on your power needs.
Both the 5v and 3.3v rails performed without power fluctuations and both performed very well when under a load. When the temperature started to rise I was able to hear some noise from the fan, but it was nothing that seemed to be louder than other system fans in place. The noise was barely heard, but since I was able to distinguish it I will make note of it.
Overall, the Vulcan 1200 performed very well in a system that is considered an enthusiast level rig. No matter the load, this power supply was able to handle it with no problems at all.