Hard drive and maybe the video card, I dont know to much about those sapphires though...
XFIRE: Lindmando STEAM: Lindmando
Intel(R) Core(TM)2 Duo CPU E8400 @ 3.00GHz (2 CPUs), ~3.0GHz
4094MB RAM 500 GB HD ATI Radeon™ HD 5850 8800 GT
Windows 7 64-bit Ultimate