I am having a similar issue, i can play all my games with no problem at all, but sometimes when i'm viewing videos on chrome, it freezes.
The most efficient way to replicate this problem to me, was playing a 1080p video on Youtube (Chrome) and Extract a RAR file at the same time.
This won't help you, but if this makes your PC freeze, probably the problem is not in our GPUs, but in the driver.
Same problem here. I dont know whats going on.