GTX 260 3-way vs GTX 285 2-way SLI

Hi everyone. I'm currently running a system with the following specs..


Processor: Intel Core i7 920 @ 3.8ghz
RAM: 6GB Corsair Dominator DDR3 1600 8-8-8-24 1T
Video Card(s): 3x EVGA GTX 260 216 Core Superclocked Edition @ GTX 280 FTW speeds
Motherboard: EVGA 1366 X58
PSU: Corsair HX1000 1000W
HDD: Seagate Barracuda 500GB 7200.11 32MB Cache
OS: Windows Vista Ultimate 64-bit
Case: Antec Twelve Hundred
Monitor: 26" Samsung SyncMaster T260

I'm seriously considering stepping up two of my current GTX 260's for two GTX 285 and selling my third card and then buying a high end sound card. The main reason why I want to do this is for the addition of a nice sound card. Also, as a side benefit it would take some load off my PSU even though it handles my current setup rock solid and like a champ. The main thing I'm concerned about is losing performance over my current setup. I would overclock the two GTX 285's pretty heavily and to at least the SSC speeds. This would obviously give them that extra edge. So would I lose performance in games by switching over to the two GTX 285's OC'd a respectable amount? I'm current able to play games like Crysis @ 1920x1200 8xAA and Farcry 2 1920x1200 ABSOLUTELY maxed out with all the settings. Will I still be able to with the two GTX 285's and will they play all the games maxed out until the GT300 DX11 cards come out? I know they would score less in benchmarking but I'm just worried about actual FPS in games. I'll keep this short as possible, the main question I'm asking is will I lose any performance in gaming switching over to two heavily OC'd GTX 285's?




-Thanks