I have a lot of fans in my system and I had to really turn down every other fan and listen really close to hear these fans at all. At about 1100 RPM I could start to hear them above the system noise in my PC. When comparing these to the original stock fans - all three Spectre fans running at 1200 RPM are still much much quieter than having one of the originals running full blast. . .
Any major computer upgrade generally requires a full software reinstall too. No so if you heed the advice in the guide to Upgrading a Motherboard without Reinstalling. PCSTATS Tips