Crossfire PSU question

I currently have an Enermax Infiniti 720w Modular PSU. I am going to be upgrading to putting 2 6870's in crossfire and want to know if this PSU will work?

I will be upgrading my system, so ignore my equip listed (except PSU of course LOL)

 

It could work but it might be a stretch depending on the other components.

 

I think that the most important (12V consumption input and amps) are the features of your PSU you should check.
Your PSU should provide enough power on 12V for 2 of these cards.
As far as i know, a 6870 crossfire should almost reach 40A on combined rails.
So now it's up to you to check these features on your PSU.

 

k4sh... what are you smoking? two 6870s wont use anywhere near 40a.

each 6870 uses around 140w. 2x 140w = 280w. 280w / 12v = 24a. as long as OP has 24a on a 12v rail that isnt shared with the cpu, he's fine. his power supply can handle crossfired 6870s without breaking a sweat and still have plenty of breathing room for OC.

 

Did not smoke anything. according to this site ...
http://forum-en.msi.com/index.php?topic=104805.0
A 6870 crossfire config would need a minimum 38A 600W PSU.
I guess this is the whole system consumption as it counts "basic" components.
But it's not so far to what i told just before.

 

My PSU has 3 12v rails rated 28a,28a and 30a respectively. My concern is, it only has 2 ci-e 6 pin ports on the back of the PSU (modular). Doesn't the 6870's crossfired need a total of 4 8pin connectors?

 

hmm, didnt google the specs but yeah, you do need 4x 6pin. you can always use molex adapters, but its always better to use a direct connection from the psu.

if youre up for it, you can look around for a cheap brand name psu that dumps all its amps in the 12V rail and run that as a piggyback-ish psu to power the second card. i think thermaltake have a psu thats designed to run as a secondary psu.

 

Doesn't the Infinity 720W have cable management? There should be additional PCIe cables included that you can connect to the psu.


Edit: The psu has 3 PCIe connectors in total so you would have to use one molex connector.

 

I use 700w with 58,3a on 12v rails, also needed 2 molex > 6pin adapters.
But they have 2 molex on 1 6pin if i connected both molex my PC didnt started anymore.
So if u run into that problem only connect one molex on the 6pin adapter.

So far i dont ran into problems, only that they overheat a little around 80c-87c.

 

Why it wouldn't? That's more than enough.

 

I think that should be more than enough for 6870 Crossfire!

 

So how many 8 pin connectors does the 6870 have on each card?

 

Two 6 pin connectors each.

 

Thanks