I recently had to RMA a graphics card to MSI because the last stopped working due to unknown causes. It ran perfectly well, with very stable temperatures of around 60-70c under heavy load. They swapped that graphics card for a new one, and sent it on over, and now I'm having issues where my GPU runs at 30-35c while on desktop, but as soon as I run a game, the temperature skyrockets up to around 90-100c. What might be the cause of this? The fans are working properly and it is not overclocked.
Motherboard = Asus P8Z77v-pro
CPU = Intel i5 3570k
GPU = MSI Radeon 7950 Twin Frozr III
Edit: Checked the thermal paste/heatsink, all seem to be fine.
Update: Just going to RMA it again. Got off the phone with tech support and they said that the card they swapped it with (not new as I expected) had critical overheating issues. Not a surprise. Thank you for the replies, think i'm going to stick with Nvidia after this.