Now all I need is a way to make the setting permanent. You might have noticed that the last 4 digits are the fan speed (in hexidecimal) This will set CPU Fan to max at the default 3900 rpms Press and hold the keys as soon as you see the startup screen and hear the startup sound. Hold the buttons down if the screen goes black until you hear a tone or see a gray Apple logo on a black background. Applications/smcFanControl.app/Contents/Resources/smc -k F2Mx -w 3cf0 If your Mac is already running, close any open programs before holding the keys for roughly 20 seconds. This will set the CPU Fan to max at 1200 rpm: (Oh yes!) Applications/smcFanControl.app/Contents/Resources/smc -k F2Mx -w 12c0 Go to the terminal and use these commands to regain control of your noisy iMac: Using terminal commands there actually is a way to force smcFanControl to set a tolerable max rpm for the CPU fan.īe aware that this solution should only be used if you know what you're doing and you are absolutely sure the CPU fan on your iMac is indeed out of control.įorcing a low max speed on a healthy CPU Fan with fully functioning sensors can seriously damage your Mac. The ideal solution for me would be a way to limit the CPU Fan to the usual 1000 rpms and prevent it from going higher. I'm ready to try creative solutions as this is my last resort and the next step is 'retiring' the iMac. Finally after two failed attempts to repair it Apple replaced it with my current model that shows the same annoying behavior. My first iMac had the exact same problem (Racing CPU Fan) and spent most of its short life in the repairs. I have been a very happy switcher for more than 2 years now, but with this being the second iMac of mine to show this behavior, I'm starting to losing faith in the iMac cooling fan system. There's numerous threads about racing and noisy fans on the boards but none with a definite solution to the problem. I have already tried the following to no avail:Īlso SMCFancontrol won't help as it can't slow down fans only make them go even faster (I definitely don't want that). IMac (Early 2008) Intel Core 2 Duo 2.66 GHz, 4 GB RAM ![]() Even after hours of useless fan spinning has left it freezing cold. Never spins down again unless the iMac is reset or put to sleep. Once the CPU fan has spun up to its max it Usually putting the Mac to sleep and waking it up slows the CPU fan down, but it will go nuts at 3900 rpms soon again. The noise usually starts within the first 10 minutes of usage but sometimes it can go noiseless a bit longer.Īctivity Monitor shows no heavy processes running to justify the noise (no Spotlight indexing or anything) and the temperatures are as low as can be. My iMac suffers from excessive noise from the CPU fan.
0 Comments
Leave a Reply. |