How shall I power my GPUs?

[NIDAN17]

Hi guys,

I currently have a 7850 GPU which is powered by a 6 pin power connector. I have just bought a 7870 to xfire with it but found out after getting the card that it needs 2 6 pin power connectors. My PSU only has slots for two 8 pins as seen in this picture: http://ic.tweakimg.net/ext/i/imagelarge/1260459909.jpeg

I know xfiring is often frowned upon but I'm only doing it as an interim before getting my new computer next year after Skylake has come out and I have the money for a new one.

A friend suggested using a molex to 6 pin connector but i'm not sure where I would plug the molex into on the PSU. I can plug the 7870 in with the other 6 pin that came with the PSU but it needs 2 6 pin connectors.

Sorry if this is a stupid question but this is the first time I've added a second GPU and I've only ever built one computer before (this one) which I haven't touched the PSU since building it.

Thanks in advance

 

[Snortan]

CrossFire isn't frowned upon, or sli for that matter, it just makes more sense(headache wise) to buy the best single card you can instead of two less powerful ones.

He's talking about something like this http://www.amazon.co.uk/Akasa-AK-CB4-6-cable-adapter/dp/B00118EWLS . You connect it to two molex connectors (not the psu side but the other end) so check you haven't occupied all your molex/peripherial connectors first.

 

[NIDAN17]

ah ok, one of these came with the 7870 that I got: http://www.overclock.net/content/type/61/id/1189849/width/350/height/700/flags/LL

what would I plug the molex end into? A female molex to 6 pin?

 

[Snortan]

Yes, you just plug the male molex adaptor in the female that comes from the PSU.
Does the cable you have, have just one molex connector or two? Haven't seen any yet with just one.

 

[NIDAN17]

Yes, you just plug the male molex adaptor in the female that comes from the PSU.
Does the cable you have, have just one molex connector or two? Haven't seen any yet with just one.

The attached image is the actual cable that came with the card. It has just one

 

[Snortan]

From what I've read you should use two molex to one 6pin like in the example I showed above so you have 6 total pins (3 pins per connector) in molex to the 6 pins in the GPU connector.
But if that adaptor came with the GPU I assume it's safe to use it, however I'd try to get my hands on the other type of adaptor just to be on the safe side.

 

[NIDAN17]

So I need one of the adapters that you linked to me and then plug that into the whatever pin to molex that came with the psu?

 

[barnsley]

Whats frowned upon is using molex to 6 pin. Also I'm not entirely sure if mixed crossfire is still a thing.

 

[Snortan]

So I need one of the adapters that you linked to me and then plug that into the whatever pin to molex that came with the psu?

Yes. Also the each molex connector from that should be connected to a different molex cable from the PSU. I see you have 2 cables for molex/peripherals.

Whats frowned upon is using molex to 6 pin. Also I'm not entirely sure if mixed crossfire is still a thing.

While I agree, plenty people have used it in the past without any issues, me included.

 

[NIDAN17]

Whats frowned upon is using molex to 6 pin. Also I'm not entirely sure if mixed crossfire is still a thing.

What do you mean, mixed crossfire isn't a thing anymore? does catalyst not support it? The AMD website says you can still do it (or at least from this chart) http://support.amd.com/en-us/kb-articles/Pages/Crossfire-Chart.aspx