Cant see any video mate ..
Very common problem this one but incredibly odd that it's just started happening.
Have you looked at your Windows Update history and possibly done a system restore?
It might be an update that's done this. I had one a while back that made the windows on my PC take around three seconds to open and close,almost like they were in slow motion.
Try going back to stock overclocks? In a few of my games if i go above 1000/1250 then it just freezes and or drivers crash. At stock 960/1250 it's perfectly fine though. Maybe you might have this problem?
Take out one card at a time and do trial and error to see if one is starting to die?
But does it still fold ok?
yeah might have to try that