In last couple of days, one my computer's fans spin loud everytime i start up the computer. It lasts 30 or so seconds before it goes away but sometimes it spins loud again in the middle of the day. I want to know which fan is spinning loud that way, so today i open up the computer and turn on to see which one is spins. Turns out that the heatsink on my Sapphire Radeon X700 Pro was the one that was spinning loud. Any reason why? BTW, it happened before a couple of months ago.