Using the most recent Nvidia driver (I'd have to look up the exact number) should solve those issues, but I suppose that using the earliest Kepler driver could help too, although that is odd for a CD driver to work better than more up to date drivers IMO. If not, then you might have a hardware problem somewhere. The card might be faulty, your PSU might be faulty, or maybe another less likely possibility. The games themselves might have problems right now and maybe there are updates that help. These aren't the only possibilities, but they are a few likely causes of your problems.
Don't count off the PSU just yet. Let's read its specs and age before we dismiss it. The PSU is often dismissed as a problem despite being one of the more likely possible causes in almost every such computer problem. What model is it, how old is it, and have you been pushing it anywhere near it's maximum rated 12v amperage(s)?
What wattage? What are the rest of the components in your computer? Also, unless you test the graphics card with another PSU or even better, the entire computer with another PSU, don't count it off. It probably isn't the problem unless it doesn't have enough wattage given that Corsair is a good vender and it is fairly new, but Corsair, even though they might be the best PSU company (or are at least in the top few), is still not infallible. You might have a slightly faulty PSU. Probably not, but it could be the problem. However, I think that the card itself might be a more likely cause of your problems. You could try testing another such card if you can get one, maybe you could simply try an RMA or at least talking with the company who *made* it. It's hard to give advice given that we need more info to see at least most of the whole picture here.
If not for the drivers all not helping, I'd think that the drivers are the most likely cause and maybe they are, but it'd be odd if you're affected in such a way when I've not heard of drivers causing these problems completely with anyone else. Perhaps you're one of the first, but it looks like the drivers aren't the problem if I had to guess.