Just posting my personal experience here for anyone wondering. I've got a new Hex running dual monitors from a 5870 (30" Dell 3007 via DL-DVI and 24" Samsung via MDP) without any issues. No snow, no black screens (so far anyway) and no sleep issues. I've also been working on a 2010 8-core we just got at work which is running 2 x 24" Samsungs via 5870 without issue. No sound pop issues on either. Maybe there are just some bad batches of 5870's out there? I wonder if anyone is installing 3rd party drivers for monitors? I don't ever install any drivers, just use the built-in Apple support. EDIT: Can anyone having the 5770/5870 problems recommend any ways I can try to make the snow/black screens happen? Or is it totally unpredictable? I've got PS and Lightroom open right now. Could've sworn I saw a now blip when I launched PS, but maybe I'm imagining things now. I'm willing to test the 8-core, too, if there's anything I can specifically do.