Got a new Gainward 600 Golden Sample today. 64MB of 4ns DDR...nice red PCB...lightweight cooling, but Ok.
The drivers provided by the vendor blue-screened, and wouldn't complete the 3DMark Lobby High Detail test properly (didn't die, but the characters were only visible as intermittent flashes, and occasional shadows). I tried several downloaded versions but settled on 27.70 betas that are only about 2 weeks old.
The scores at default settings were about 5200. I have cranked the core/mem up to 300/450 and the scores came up to 5600. No instability yet, I think I'll run it here for a day or two before tightening it up a bit more.
It is a damn shame that Nvidia still can't write decent drivers.
Free advice, and worth every penny.