1 SATA drive is for OS and all applications
1 SATA drive is for backup/sync (i just don't remember turn USB HDD on, so i bought internal HDD for backup/sync purposes)
CPU is constantly in use, i'm SETI@home fanatic

Cool n Quiet is disabled due SETI@home
EDIT: OMG, 5870 ares costs ~1100

EDIT2: OK, so if not going totally overkill. If i change MOBO, i think this would be best: ASUS Crosshair IV Formula (As it has 2x PCIe 16x slots. For gaming i mean it's good) and what GPUs i should chose? Also is my 750W PSU good enough?