Hello , some quick setup on mine HD4850 with 3x card from three brand too, ASUS, Sapphire and PowerColor

Setup...
QX9770@4.5-4.6GHz on water
ASUS P5E64WS Evolution
CellShock 14400C8@1600 CL6-6-6-15
ASUS EAH4850, PowerColor HD4850, Sapphire HD4850 (16x+16x+4x)
ASUS PhysX
WD Raptor
Gigabyte Odin 1.2kW
Vista Ultimate+Catalyst 8.6

Setup Pic.


Results...
2k3


2k5


2k6


Vantage(Performance)


btw. i'll update again with 4x CrossfireX next time, waiting for receive another card about this sunday

Thanks