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.