On Sun, 28 Dec 2008 07:22:40 +0100, Aragorn wrote:

The motherboard is an Intel server board - I think a 7500CW - with two
Intel Xeon 2.2 GHz (400 Hz FSB) 32-bit processors with hyperthreading.
The memory is 4 GB (4x 1 GB) Transcend ECC registered DDR-266, running
at 200 MHz. /memtest86/ shows no errors whatsoever, and the power
supply is 350 Watts but doesn't pull more than 220 Watts during boot-up
and appears to check out fine.

Overall voltage potential of the power supply is effectively irrelevant.
Voltage draw per rail per device must be calculated.