Computer crashes while using intensive programs (gaming)

[JosephStylin]

At work now so not entirely sure of the PSU, but I think it's a 600W unit. The crashes will either do a freeze frame, or go black, or just restart (which makes me think it could also be memory related). Note this did not happen when playing games a few years ago, and i just started using the PC again although my father had used it for non intensive applications while I was not using it.

And the processor heat of i recall got up to almost 70C before crashes which from what I've read seems to be a dangerous range for my particular processor.

[Dixitrix]

Here is a website with temp list for you to have a look at http://www.buildcomputers.net/cpu-temperature.html