When it comes to testing a power supply, there are a lot of choices in how to tackle the job. I have found that while a multimeter can give scads of data, most of us don't have a clue what all these facts and figures mean. Even the elite of the enthusiast crowd doesn't always keep up with the inner workings of a power supply. So what do we do?
Since a majority of our readers tend to be deeply into overclocking their systems, why not run the power supply in an overclocked system and then stress it out? After we get things worked up nicely by running 3DMark loops and burning CD disks, we'll take a reading of the power levels right in the middle of this mess. This ought to give us a workable answer as to whether or not this product can give us the power we need under stressful conditions. If it can give solid results under this type of operating condition, it will let us know that it can handle the regular chores that we are likely to throw at it.
Test System Setup
Soltek 75MRN-L Motherboard (nForce2 chipset)
Athlon XP 1700+ @ 2.1GHz
Cooler Master X-Dream SE HSF
2x 512MB Crucial PC2700 DDR
Sapphire Radeon 9800 Pro
D-Link 10/100 NIC
TDK 52x CD-RW
Pioneer 16x DVD
Western Digital 80GB 8MB Hard Drive
Seagate 40GB 2MB Hard Drive
Sony 3.5" Floppy Drive
5x 80mm case fans
1x 120mm case fan
Alright then, the processor is running at 1.65v, the memory is at 2.7v and the AGP is at default. The system is overclocked and the video card is known to cause weaker power supplies to cringe in terror. Add the stress factor and we should get a fair look at what this PSU is capable of.
As a final note, most manufacturers claim a leeway of +/- 5% of any given output level. Using this as a common ground, we should end up with rail voltage levels of 3.135-3.465v on the 3.3v rail, 4.75-5.25v on the 5v rail and 11.4-12.6v on the 12v rail. Keep this in mind when we go through the numbers below. Higher values can be beneficial, lower values bear watching.
When looking at the processor power levels we see that it has delivered exactly what was set within the BIOS. This is a good thing as it will aid you in determining the amount of heat output of the processor when deciding on cooling methods.
While the 3.3v rail is a bit lower than the full power limit, there isn't much of a lack here so it won't bear any special attention. The 5v rail is making some extra juice, so this can be beneficial when it comes time for overclocking individual components.
The 12v rail is a bit low, but is still within the 5% window. This will often be one of the most abused power rails within a system since so many add-on peripherals use this. Between the multiple fans, the Radeon based video boards and sometimes lighting effects, you can really stress this area of a power supply. But this 400w model is set up to handle an 18 amp draw on the 12v rail, so you should have a good deal of overhead before you start looking at alternative power considerations.