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Hey all,
I have just bought a second 8800GTX but my 750w power supply only has 2 x 6pin PCIe power connectors, I need an additional 2 as the 8800GTX's take 2 each....
Like these:
Newegg.com - APEVIA 9" 6 pin PCI Express Power Splitter Model CVTPCI12 - Retail
I cannot find any anywhere in the UK at all.
Can anyone help?? :O_o1:
Cheers!
its not a solution for you as you need more cable thickness to carry the ampage, try the 2x4 pin to 6 pin versions
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that way you can draw the power from 2 other cables and leave the dedicated pci-e alone.
all i would do is buy 2 of those and use one on each card, then you can use the original to feed the other socket on each card.
I only have 2 spare molex ... well, there's actually only 2 on there full stop, the rest are SATA power of which I have only 2 spare but if I use those then i'll not be able to add any more HDD?
what is this 750w psu you talk about ?
Yes for a supposedly 750w PSU that seems very few connectors . . .
Not really, I'll explain.
The 2 optical drives run from SATA power
The 2 HDD's I have run from SATA power
There's 2 extra SATA power for 2 more HDD's
There's 2 6-pin PCIe connectors (but this is a prob as the 8800GTX's use 2 each)
Leaves 1 floppy power connector and 2 molex connectors free.
I'ts a Dell XPS 720 system with the Dell 750w PSU.
I'm considering downgrading to 2 x 8800GT's now or just sticking with the 1 8800GTX as there's no way im spending £150 on a 1000w Dell PSU that has 4 6-pin PCIe connectors (has to be Dell as they use propietry mobo connectors)
You don't buy Dell to upgrade. That, in a nutshell, is your problem. However you can buy 1 molex to 2 molex splitters. Whather the Dell 750W can actually handle the 12V draw is something I wouldn't like to guess.
Ahhh Dell, that explanes the odd number of connectors.
eg my OCZ GameXStream 700w (Yes I do realise it is a truely massive overkill psu for my pc) has 2xPCIe 6xSATA 6xMolex 2xFloppy disk
So 2xPCIe 6xSATA 2xMolex 1xFloppy is rather few for a 750w PSU
You could try contacting dell and seeing what they say, although my guess is they'll try to flog you a 1000w PSU.
Bumping this thread - I am in PRECICELY the same situation, OP, and I would love to know how you resolved this in the end. Please help!
Better late than never in contributing to this thread - I have succesfully run two 8800GTX's using the 750W power supply on an XPS720.
Don't bother with the molex splitter route - these won't supply enough power and this will result in the GPUs going into low-power mode (reducing performance by 2/3-3/4).
What you need to do instead is use the peripheral connector (labelled P14, intended for the H2C's TEC cooler - see page 149 of the XPS720 Owner's Manual for pinout details) to power the second card and this will require a little more work. The most elegant option would be to crimp your own cable to connect pins 1 and 2 (yellow and black) and 3 and 6 (yellow/white and black) to 2 6-pin PCI-E connectors.
The route I followed (less elegant) was just to cut wires 1, 2, 3 and 6 from the P14 connector, strip the ends, and use a connector block to attach them to a pair of 2-core cables. Each cable is then attached (via another connector block) to a 6-pin PCI-E connector (just cut off the Molex connector).
Obviously, this is going to be way outside of any Dell warranty (and would likely have most Dell engineers in stitches) but it does work and as long as the wiring is done competently, should pose no safety risk. The peripheral connector takes its supply from different 12v voltage rails (A and D) to the existing PCI-E connectors (B and C for the 750W power supply) so there should be no risk of overloading the PSU.
The maximum power draw I have seen (measured at the wall socket) with this setup (XPS720 with 5 hard disks, twin 8800GTX's, a Q6600 processor and 2GB RAM) has been 550W which should leave plenty of margin for overclocking.
The one issue left is getting an SLI connector (Dell don't include them with single GPU systems). A flexible ASUS connector does the job nicely - Dell's own SLI connector (part number MJ247) is apparently no longer available but when it was, the asking price was over £50. :eek: