Please explain PSU connectors to me

richarda83

Distinguished
Feb 15, 2010
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0
18,540
I have a HD4870 video card that I plug 2 6pin pci connectors into from my power supply. Whenever I start games in higher graphics setting the card loses power its seems cause the fan cuts out and the screen goes blank, and then it comes back, sometimes with the driver failing. I know I have the right drivers so Im looking at a new PSU.

My question is the one my friend will sell me comes with 2 6 pin connectors. It says it is SLI ready. So, hypothetically, if I wanted to add another card, I wouldn't have the cables for it. Are there older graphics cards out there that just take one 6 pin connector thus his psu could supply two of those. it seems as those cards have gone from 2 6pin to 2 8 pin on the higher end. Is this correct?

Any help would be appreciated
 
Solution
The guide I have says 600W for Crossfire 2 4870s. Get an XFX 650W for you 4 6-pin PCIe.

Each 6-pin can supply an extra 75W to the card.

this reference is a bit dated but the description is sound
http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral

You can see what he says about the molex and possible output. It really depends on wire gauge and length on whether it can supply 75W on the 12V. I think that is why sometimes the molex to 6-pin don't work.

ThePubNub

Reputable
Apr 12, 2014
8
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4,510
A reputable brand for a PSU is always a good place to start. If you're looking to run 1 graphics card and not looking to go SLI/Crossfire I would recommend a 550w but if you're looking in to the long term and want to SLI/Crossfire even if it isn't the card you have now I would recommend a 750w just remember to look at how much power you use. To get a rough idea of how much power you use, use a PSU calculator like this one (http://www.coolermaster.outervision.com/).
 
The guide I have says 600W for Crossfire 2 4870s. Get an XFX 650W for you 4 6-pin PCIe.

Each 6-pin can supply an extra 75W to the card.

this reference is a bit dated but the description is sound
http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral

You can see what he says about the molex and possible output. It really depends on wire gauge and length on whether it can supply 75W on the 12V. I think that is why sometimes the molex to 6-pin don't work.
 
Solution