Had the same problem with the noisy chipset fan! My original one is a T&T 4010H12S. I found a japanese page with the data for this one: 0.18 A, 8.5 cfm, 6000 rpm and 28 dBA. My choice now is a SilenX iXtrema Pro 40/40/10 with: 0.02 A, 5 cfm, 3000 rpm and 14 dBA Bios says it turns with up to 4000 rpm...