Hardware Insights Forum

No idea, but I've seen plenty of manufacturers do it. The Antec VPA500P I recently reviewed had some 16V caps on the 5V and 3.3V rails.

I use an old PowerEdge server as my desktop and it uses this PSU.

My question is regarding the 12v rails. The server is notoriously fussy with graphics cards but I have read that the BFG 8800gt will work with the motherboard. So I bought one and installed installed it. My computer will pass POST and I can use BIOS but when I try to boot into an operating system it immediately restarts.

The graphics card requires 24-28a on the 12v supply and the sticker on the PSU says 18a on three of the rails and 16a on the forth rail.

Is this PSU a true multi rail PSU, and if so does this mean it won't be able to fulfil the 24-28a requirement? I have read that some 'multi-rail' PSUs are actually a single rail that has been split into multiple rails. In this scenario you can combine the ampres on each rail... giving me 70a = dead graphics card!

Thank you for any replies

This unit does indeed have split OCP, but as far as I know, exceeding the trip point should cause the PSU to power down, not reset the PC (unless the PSU manufacturer did something really strange with the protection circuits).

But according to this site, the thermal design power for an 8800GT is 125W - a little over 10A worth. I assume that the "24-28A" number you reference is some recommendation for the total output from the 12V rail, with some margin in an attempt to compensate for dishonestly rated PSUs.

By the way…

70a = dead graphics card!

The PSU isn't always delivering its rated output. It delivers as much current as the loads demand - no more, no less.

If it followed that common misconception, then nothing to do with electricity would work correctly. Power circuits feeding outlets in most buildings have capacity between 10 and 20 amps but few appliances actually require an entire circuit worth of current (and in Australia, practically none as we usually have 16A power circuits, but normal outlets here are rated for a maximum of 10A each).

If you're not convinced, then look up Ohm's Law and come back when you're done…

Try the card in different computer first, it is very old and possibly somebody scammed you for deffective one.