nvidia cards and power

[Pob255]

Current situation

I have a 700w OCZ gameXstream psu and a 9800gtx
I'm currently looking around for a 2nd 9800gtx to sli them once I go over to socket 1156
The question is how to go about powering the beasties.

My psu has 4x 12v 18amp rails
the break up is like this

12v1 = 6pin pci-e1
12v2 = 6pin pci-e2
12v3 = 4+4pin eps & molex leads
12v4 = 20+4pin motherboard lead & sata leads
(ok the molex and sata might be around the other way)

main point is the there is only 2 pci-e leads and each is on a seperate rail
the 9800gtx doesn't need 18amps, it only around 10amp at 12v the reason for two pci-e is for added stability/incase of bad psu's

so how should I go about powering 2nd card?
I was thinking about some form of pci-e splitters.
Also considering the idea of selling my 9800gtx and buying a pair of 4850's

[kalniel]

Card 1: 12v1 + 12v3 (molex->PCI-e adaptor)
Card 2: 12v2 + 12v3 (molex->PCI-e adaptor)

(Replace 12v3 with whichever one your molex is on basically.) Good luck finding a sata->PCI-e adaptor.

The cards will draw most from the dedicated rails (no matter which socket they are plugged into), sipping only from the molex rail if they have to.

[Pob255]

The issue with that is molex to pci-e adaptors, are 2 molex to 1 pci-e, so that would need 4 molex's which would be a total mess to try to cable.
Have to double check the total number of connectors, but I think it's 2 cables with 3 molex on each, one currently used for ide hard drive one for fan controller

why I was thinking pci-e splitters and cross load them,
ie
card 1
port1 = 12v1
port2 = 12v2

card 2
port 1 = 12v2
port 2 = 12v1

[barwell1992]

^^ that means you will be runing 2 cards from 2 12v in stead of 4,12v lines what you could do is get a 6pin exstension cable and then use the 4-6 pin conver behind the motherboard tray or somthing

[kalniel]

The issue with that is molex to pci-e adaptors, are 2 molex to 1 pci-e

They needn't be. Mine is a 1 molex to 1 pci-e - it doesn't make any difference if you were going to take it from the same rail anyway.

I was thinking pci-e splitters and cross load them,
ie
card 1
port1 = 12v1
port2 = 12v2

card 2
port 1 = 12v2
port 2 = 12v1

And you were saying about a mess? I wouldn't do it myself, looks like it's asking for trouble.