On 30 Jun 2004, at 15:52, fictionmusic2000 wrote: > > Go here > ftp://ftp.apple.com/developer/Tool_Chest/Testing_-_Debugging/ > Performance_tools/ > > and download CHUD > Install and go to the window that says Nap and click it so the check > mark > goes on. That should do it. > > I thought it was take NAP off (not ticked) in the Hardware preference pane - as it is the constant cycling between NAP state and non-NAP that causes the chirp On my G5 Dual 2 GHz I found that disabling NAP eliminates the chirp but causes the internal fans to run significantly faster = louder For Logic I work with NAP switched on (ticked) without noticeable sound pollution issues. This is with a MOTU 896 Firewire interface. I have never tried the built in audio which is where most people have reported problems. Maybe we have better earth grounding in the UK!!! FYI - There have been two firmware releases for the G5 and after each one the fans have run faster but the chirping has remained. An initially silent machine is still very quiet but it does give out an audible low frequency rumble. I occasionally use Dreamweaver where the chirp is unbearable due to the context sensitive mouse position. This puts uneven demands on the processors. For this I switch off NAP. Logic seems to place a more even demand so I don't notice much chirping. Take your pick on which option works for you. Regards, Stuart