My 7970 died after 7 months of running at 85C overclocked as high as it would go, ever since I ran Furmark for few hour stress test the temps had been far higher and I think that was the culprit tbh, still mined fine with no hardware errors but games would crash after minutes, odd.

Still got a full £315 refund the week after the R9 series were announced, nice one amazon!