I know a lot of people encounter the issue when connecting audio interfaces(haven't found any info on other devices), but to this day no one seems to have resolved it. Therefore i'd like to reopen the discussion on the infamous Firewire coil-whine/high-pitched-noise-thingy.
facts from the previous topics found around the web:
1. The sine around 8kHz is coming directly out of the PSU or motherboard(on MBP people say it's coming from an FW port) only when the FW device is connected to no matter which port.
2. The noise disappears completely when CPU is under load.
3. People reported that it started happening after an SMC update some time in the past and didn't appear with the SMC firmware that came originally with cMP 2010.
4. Apple of course completely disregards the issue, one person even having 3 new MBPs replaced over and over meaning it's a design flaw not just a worn out PSU.
5. Some people also reported it started happening after Apple changed the Firewire chipset.
My own observations:
1. Connecting the device (and ofc producing the noise) very slightly raises the CPU usage, power consumption and temperature.
2. The issue disappears completely while bootcamped in Win7.
Any ideas if it's possible to have it somehow fixed? My guess is it has something to do with firewire power handling, but not by the SMC(to which the pre-update noiseless situation would point) but the firewire kexts, since it's working completely fine under windows drivers.
EDIT: adding some screenshots including an RTA with omnidirectional mic placed above the RAM slots(highest level encountered there).
facts from the previous topics found around the web:
1. The sine around 8kHz is coming directly out of the PSU or motherboard(on MBP people say it's coming from an FW port) only when the FW device is connected to no matter which port.
2. The noise disappears completely when CPU is under load.
3. People reported that it started happening after an SMC update some time in the past and didn't appear with the SMC firmware that came originally with cMP 2010.
4. Apple of course completely disregards the issue, one person even having 3 new MBPs replaced over and over meaning it's a design flaw not just a worn out PSU.
5. Some people also reported it started happening after Apple changed the Firewire chipset.
My own observations:
1. Connecting the device (and ofc producing the noise) very slightly raises the CPU usage, power consumption and temperature.
2. The issue disappears completely while bootcamped in Win7.
Any ideas if it's possible to have it somehow fixed? My guess is it has something to do with firewire power handling, but not by the SMC(to which the pre-update noiseless situation would point) but the firewire kexts, since it's working completely fine under windows drivers.
EDIT: adding some screenshots including an RTA with omnidirectional mic placed above the RAM slots(highest level encountered there).
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