Putting together a pretty big build, having trouble figuring out what power supply to get, I will be running 3 way HIS 5870's, so I need something that can run these cards in 3 way crossfire. Case is A COOLER MASTER HAF 922, MSI 890FXA-GD70 AM3 AMD 890FX SATA Motherboard with a 955 black edition phenom. Any tips would be good, The only psu I see is this one, and im not sure if it is what I need
Honestly, if you have not got the cards yet, i'll recommend you to keep it to a two card setup.. You may get a third Nvidia card for physx.. Now assuming your processor overclocked to 4GHz along with 3 of those 5870's and few other standard components, you'll surely need in excess of 800 watts.. The Corsair TX 950 would suit your setup.. But its non-modular.. Might want to go for the HX 1000 here..
I agree with Emperus. If possible, don't go for three graphics cards. If you haven't brought them yet, then just buy a 68 or 69 serious radeon. 2 of those will have more juice in them than 3 of your 5870s, and you'll probably come out keeping some money in your pocket too. As far as PSU's go, if you really want the three-way set up then you need to be looking at the 900 boundary and above. When it comes to PSUs the last thing you want to do is cheap out, because your system WILL **** up and the repairs will cost you a bomb. So I would recommend a Corsair TX or HX serious PSU. Hope this helped.