Finally! The problem appears solved. After researching for hours and trying 5 different apps and potential fixes - I seem to have found two working solutions. By the way, I have a SR Macbook 2.0 - Leopard 10.5.1 Solution 1: Download and install: ftp://ftp.apple.com/developer/Tool_Chest/Testing_-_Debugging/Performance_tools/CHUD_4.4.4.dmg This will add a new option to system prefs. After installing, go to system preferences -> hardware -> processor -> "show control in menu bar". Now in the menu bar, click on the processor icon and select "show processor palette". Then click on the second processor icon/picture to grey it out OR simply select "single cpu" from the drop-down. Now your system will only be using one processor, and for me, the whine has stopped completely! HINT: Do not uncheck/check it through the system prefs panel - it doesn't work for some reason. Use the menu-bar-palette way or menu -> single cpu also works most of the time. Sometimes you need to enable/disable the processor several times to get this to work, I don't know why. Just have you ear close to your macbook and enable/disable the 2nd processor until the noise is gone. This sounds stupid, but it does work after you've tried it a couple of times, once you "get it" the noise stays off until you sleep/restart. I monitored my CPU temp and it does NOT increase, no fans spring on. Now I can finally love my macbook! I'm happy Drawbacks: -Noise seems to kick in during screensaver, but when you log-in again/get out of screensaver its gone again. -needs to be re-done after every restart & sleep (but it only takes a second if you do top menu -> single cpu) -using only one CPU, so performance loss. Though nothing significant it seems. ------------------- Solution 2: Download QuiteMBP (works for macbooks as well): http://www.red-sweater.com/blog/downloads/QuietMBP1.1.zip Run it and set the slider to the far left to completely disable the noise. WARNING: This is a crude method, because the app will keep your CPU's busy at a minimum 38%, which means your core temperatures will increase by 30-50 degrees Farenheit, which means the fans will kick in, permanetley (as long as you run QuiteMBP) and this in turn means less battery life and the fan noise... Hopefully Apple will release an official fix for this sometime soon, but I doubt it because the problem has existed since 2006 at least. Any feedback is appreciated!