It looks like I had a bad RAM slot. I've gone back to the nvidia card and everything is OK.

NevilleGoddard wrote:It looks like I had a bad RAM slot. I've gone back to the nvidia card and everything is OK.

Ouch! That's a nasty thing.
bad ram/bad ram slot can lead to programs abortion, kernel panic, data and/or program corruption ...

It certainly is a bad thing. Luckily I have 4 ram slots. The RAM sticks were originally in slots A2 B2 now they're in A1 B1 and everything seems to be OK. However I only have single channel RAM which means I only have 4gb not 8gb of RAM.

The BIOS sees both 4gb sticks and says I have 8gb RAM but for some reason it is stuck in single channel mode. This means I think that there is something wrong with my cpu's ram controller. I'll try to fix it later.