Crossfire, PSU's and Cooling Loops

fergie128 · 22 Jul 2008 at 15:52

Planning to add two 4870 X2 2gb cards to my system, and im a little worried about power!

I have my system set up with 2 independent cooling loops. 1 flows through the cpu and mosfet blocks, the other for graphics cards.

What i am wondering is, would i be better going for 1 monster psu (was thinking a 1300 Tagan - http://www.overclockers.co.uk/showproduct.php?prodid=CA-019-TG ) or would i be better going for 2 smaller PSUs, one for the graphics cards, and the other for the rest.

QX9770
Asus P5E Premium X48 WiFi
4Gb DDR3
CrossFire'd ATi 4870 X2 2Gb
30" Dell Ultrasharp
Mountain Mods Ascension Case

*Edit* Just read about the rippling problems with some of the Tagan PSUs, maybe better with a Thermaltake ToughPower 1500w - http://www.overclockers.co.uk/showproduct.php?prodid=CA-067-TT ). Anyone encountered any problems with a Tagan PSU btw ?

p4radox · 22 Jul 2008 at 19:02

I'd go with just the one single PSU. No point in having two.

And 1kW should be more than enough.

fergie128 · 22 Jul 2008 at 19:08

Thanks for that. Wasnt too sure myself, heard the cards can take up to 450w each under a full load. Didnt want to leave myself short

mp260767 · 22 Jul 2008 at 22:49

main thing might well be pci-e power connectors, each single 4870 needs 2, so would guess you need 4 for a 4870 x2, if thats the case you'll need 8 pci-e connectors in total.

Mud · 22 Jul 2008 at 23:22

Might as well get a PSU with 3 pairs of PCIe connectors, just in case you end up getting crazier in the future. I went 1200W simply because 1000W wasn't significantly cheaper and supposedly the lower the PSU utilisation (as a proportion of the total capacity) the higher the efficiency (though this probably doesn't hold at extremely low loads and I'm ready to be told I'm just plain wrong).

I'd vouch for my Thermaltake PSU, the rails are absolutely rock-solid, it's modular and got great reviews. That said, it is long and there's plenty of quality choices at the high-end.

shaffaaf27 · 23 Jul 2008 at 00:22

id say the tagan 800W would be fine.

but my choice i think the Be Quiet! Dark Power Pro 850W PSU will be fine

CraigN · 23 Jul 2008 at 10:23

Enermax galaxy 1000w i run it in my MM case and i will be runnign the same cards as you and i run a skulltrail system.

fergie128 · 23 Jul 2008 at 17:08

THanks for all the thoughts and opinions guys. Greatly appreciated