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Old 01-26-12, 05:11 PM   #1
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Join Date: Nov 2002
Posts: 560
Default Rearranged PCI-E cables, PSU draws less power from the socket now!

My specs are in my signature. My PSU has 2xPCI-E 6 pin connectors. I had both of these connected to graphics card #1. Then I used the 4pin molex connectors with adapters to power the second card. So apparently, my PSU has 4 12v rails. I've read that I could potentially overload one rail by eg powering a gpu off just the molex's if they happen to be on the same rail...

So... I plugged 1xPCI-E into each card and then used the 4 pin molex adapters, again one in each card. Big deal eh? Well, I have one of those gadget things that shows you how many watts your drawing from the wall socket.

I tested playing 4 rounds of BF3 on the same map, same server, same no of players.

With 2xPCI-E 1st card, 2xMolex 2nd card: 490-510 watts.
With 1xPCI-E and 1 Molex in each : 390-410 watts.

I've tested this several times because I don't see how thats possible?!? So, have I 1:- Invented a new cleaner form of electric. 2:- With 2xPCI-E in 1 card the 12v rail it was on was struggling so much it was drawing an extra 100w. Or 3:- something critical is about to fail in a really bad way if I don't return both pci-e to card 1?

I'm pleased, yet really worried. I've checked the connections about 10 times... I've had no stability problems either method.
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