My PS3 (CECH-2001A) has been running loudly since I swapped out the stock hard drive for a 1 TB 7200 RPM drive. When I say loudly, it seems that the fan inside the PS3 starts kicking into high gear sooner than usual. I've had this hard drive in my system for about a year now and have played my ps3 on average I'd say the equivalent of about 4 hours a day for a year.
Just a few weeks ago I decided that it's time to go back to a 5400 RPM drive same size. So I made the swap and turned the PS3 on. It ran A LOT quieter. But after leaving it on for about 20 minutes (had to format and re-install fw), the fan kicked into gear again. This time though it is quieter than it was with the 7200 RPM. Is this just how the PS3 fan runs? I thought it would run quietly. My wife was in the bathroom and when the fan kicked on for the 5400 RPM she shouted "What was that?" I may not have minded it before I was married but, I don't want the noise to interrupt her when she is napping or sleeping.