PCI-E version is confusing also - HD 57xx/58xx series are PCI-E 2.1
I couldn't find direct statement says 2.1 being compatible with 1.0 but 2.1 has actually the same link as 2.0 hence should be backward compatible with this mobo's PCI-E 1.0a.
from Wikipedia: "Overall, graphic cards or motherboards designed for v 2.0 will be able to work with the other being v 1.1 or v 1.0."
and got to follow HeX's advice "just knock your FSB up to 400MHz, keep your ram in sync at 1:1 (for 800MHz PC6400), then crank up the vcore until its stable." I hope it works on my E8400 so no bottleneck here
njaaahh , sry people but it's probably not me who is running P35 with HD5800. I bought HD4770 at the end of the day.
After many days and nights of testing, I m pretty sure something is wrong with my Zalman PSU at very peak power. HD4770 requires only a half of power than my present card (8800GT) so I ll give it a chance, cost only 80eur I think should be fine with all present games @ 1440x900.
Will build new system next christmas when there will be a lot of DX11 games and so more choice of DX11 cards.