I was getting these type of crashes as well on my new built system. Went though all the hardware tests for days with no fails. Started poking around with the software side of things.
The fix for me ended up being installing DX9c. Since I have Win7, I thought I was fine with DX11. Came to find out the versions of DX have their own .dlls. Read that .dlls could cause these type of issues so I gave it a go. Went from 10m-1Hr before a crash to playing 7Hrs straight with no issues.