I found a Mac version graphics card for sale locally at a very good price (HD 4870) and desided to purchase it. Right away I could see that there was dust on the fan, but went home to try out the card. The card ran very hot, and the fan speed was very high even with no real processes going on so I tried opening the card. The amount og accumilated dust (and probably tar) was incredible, and obvious that the fan was not able to get any air into the heatsink of the card. The dust was really sticking the the fan blades and took a lot of work to clean them. But after a long cleaning session and thermal paste the card runs virtually silent now, and hardly revs up when under heavy use (I actually opened the side door once just to be sure the fan on the card was running Some of the more experienced computer DIY guys here have probably seen worse, but this was by far the worst I have seen lol.