I've tested with two different setups :
1st setup :
CPU : AMD Phenom ll X6 1090T Black Edition
Mobo : Gigabyte GA-790XTA-UD4 / F3 Bios
RAM : Kingston HyperX Blu 4GB DDR3 1600MHz CL8
HDD : Samsung 320GB SATA-II 7200RPM 16MB NCQ SpinPoint F1 Series / WDC WD6400AAKS 640GB SATA-II 7200RPM 16MB
VGA : 2 x Gigabyte HD6850
PSU : Seasonic S12II-620 Bronze 620W
OS : Windows 7 x64
DRV : Catalyst 10.12a
2nd setup :
CPU : AMD Phenom ll X3 700e
Mobo : MSI 785GT-E63
RAM : A-Data Vitesta Extreme Edition 4GB DDR2 800MHz
HDD : 2 x WD 1TB Enterprise (Raid Edition) in RAID0
VGA : 2 x Gigabyte HD6850 | 1 x ASUS HD6850
PSU : Corsair CX400W
OS : Windows 7 x64
DRV : Catalyst 10.12a
Testing methods : All stock , running FarCry 2 benchmark at full details (1920 x 1080)
Results :
2 x Gigabyte HD6850 - No Signal crash , every time.
1 x Asus HD6850 - Runs fine , all 3 benches. No problems at all.
With the 1090T setup I'm experiencing another problem : when I put in a single GPU , the system randomly fails to boot (no image , no boot beep , no nothing). Sometimes it's OK , but not always. With both cards installed , my PC boots perfectly.
Can this be an issue between my mobo (GA-790XTA-UD4) and the newcomer HD6850 ? Should I try the latest bios (F4A .. yeah , beta) for my mobo ?
Also , in 3D applications , sometimes I'm getting BSODs , and it's very frustrating since with my old HD5850 everything it's perfect.
Thanks,
Seby