Hi guys
got the 4870 yesterday and some 120mm high cfm LED fans.
tried it on Zebby Pro 550 and works like a charm. For double checking, i oced my CPU to its max value at which it consumes 165W which is even higher than most quads, added another HDD, DVDRW, and ran every benchmarking softwares i cud, like 3dM 06, everest etc.
OCCT utility failed to launch saying, DX9 files are outdated, even though ive installed latest DX10 updates for vista.
So now i can say A Zebby Pro 550[HEC OEM] can handle a 4870 easily.