I have 2x Sapphire Vapor-X 5870 OC running at stock voltage (1.16 V if I remember correctly), 935 MHz core and 319 MHz mem clocks. No CrossFireX bridges. Windows 7 32-bit, Catalyst 11.5 w/ bundled SDK 2.4. Running Phoenix 1.48 + phatk. Options are: VECTORS BFI_INT WORKSIZE=256 FASTLOOP=false AGGRESSION=13. Getting 413 Mhash/s from each card. The rig is located in a conditioned room alongside other IT equipment. With both fans at 100% and with case's side covers removed core temperatures are 45C and 75C (the second card sits too close to the first because of bad PCI-E slots separation).