SLI GTX 660s power connection

ROC13

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Nov 25, 2014
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I have a Dell Precision 5400 with a 875 watt psu and one 6 pin power connector. I want to put dual GTX 660s in my system but I am unsure about how many power connectors I need. Will the one 6 pin connector run both gpus or do I need two or more and if so do I need a new psu?
Thank You
 
Use the existing 6-pin connector on one of the cards.

If your PSU has a spare 4-pin molex connector, you can buy a 4-pin molex to 6-pin PCIe converter cable for the other card.

If there's no spare molex connector you'll have to get a PSU which has two 6-pin PCIe connectors.

If you do buy another PSU, consider getting a modular one which means you won't have unused cables and connectors hanging everywhere. You only plug in the cables you actually need at the PSU end. That not only makes for a much cleaner looking and tidier cable layout, it will also allow air to circulate better to keep things cool.

 
You need as many pci-e power connectors as the gpus have total. What brand and model is that psu? Having only one 6-pin pci-e power connector at that wattage raises doubts about its quality (and the accuracy of the claimed wattage). I would expect a psu that powerful to have at least 2x 6+2-pin connectors and 2x 6-pin connectors, or better yet 4x 6+2-pin connectors.
 
First of all, does your motherboard have a second pcie x16 slot capable of running sli at X8 speeds?
If not, sli is not an option. Most pre built pc's will support only the initial configuration.
A 850w psu should be sufficient, for sli GTX660 and it should have at least two 6 pin pcie power leads.
If it does not, it must be an abysmally deficient psu that should be replaced asap.
What brand/model is it?
You would connect one to each graphics card.