sorry for this delay
tried several drivers: nvidia whql, modified, asus enhanced drivers
all 8x.xx or 9x.xx
it was impossible to
oc with one of these nvidia drivers.
I found a stable
oc with ATI Tool: 600/1080, scanned for artifacts several hours, NFS:Carbon no problem
last week I mounted the original aircooling back on that card and now? -I can
oc without any problems. I guess it has something to do with fanspeed, something like a protection or so.