4870 overheating, pathetic

So i have a fairly old computer wich i'm planning on changing whenever the 28nm hits the markets sometime next year but for now this computer will do, quad core 6600 + radeon 4870HD.

Anyway to the main issue, i recently discoverd that my gfx card was getting extremly hot and it turned the computer off, i know that this card is one of the warmest one ever made, having an idle of 79averege (according to tomshardware charts) and over 100during load.

But now i discoverd that my idle was around 90 and load was around 115 and whenever it passed 120 the computer just turned itself off, wich i guess i'm happy it did but the sort of weird part is that my fps isnt really effekted at all by my card getting extremly hot. (cleaned it and everything but the fan was just history and didnt spin at all)

Anyway so i changed the fan on the card in hope to make it live for the next coming months,, my idle got lowered to 73-75 wich is around 5-6below averege so that's pretty good. I tried to play some games, first bloodline champions wich is worked good on. around 100-105 averege temp wich is around 5-7below averege.

In starcraft it still stayed on around 105-115 but still no crash, have not tested this enough to be sure tho.

To my question than. WHY does my computer decide to turn itself off instead of just lowering how much my GPU is working?? Is this normal? Seems pretty weird to me, never had so much problem with temps befor in a gfx card and never manage to get a computer to crash because of it (even when really going all out and running around with 5-10fps in games)

Tried bf3 beta, even with lowest graphics and averege fps of 20-40 it decided it had to overwork itself and bring it up to an amazing 120c and turn itself off.

why is this designed like this

The next card i'm buying will have alteast 3fans, tierd of this overheating ***

If the GPU does get too hot, it will trigger an automatic shutdown to protect itself. Throttling only does so much, and won't be enough if you are getting up to 120 degrees celsius.

Your problem most likely is that the thermal paste on the card has degraded with age. The only way to fix this is to remove the cooler, clean and reapply the paste, and reattach the cooler. That should get your temperatures back down to an acceptable level.

Fortunately just about every card out there today runs cooler than the 4870, so you don't necessarily need to get a triple fan card in the future, not unless you plan on doing serious overclocking.