Raise the maximum fan speed?
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I was wondering whether smcFanControl is capable of raising the fan speed above the default maximum (putting aside concerns about whether doing so would be sensible)?
I did some experimenting with this idea and my iMac 5K (since thermal throttling was killing me in games) and published my results here.
Thank you, this is definitely worth a try +1
I read through your work and tried it myself on my Mac Pro (2013) running MacOS 10.15.5. If anyone wishes to follow the same process you should do so at your own risk and discretion, accepting that you could damage your computer.
I compiled and ran the smc command-line utility, using it to change the values of the 'forced' (FS! ) and 'target fan speed' (F0Tg) keys. The fan does draw power from the 12V IO Board rail, so the power draw should, in theory, be safely limited. The true maximum fan speed is a little over 2600RPM, rather than the usual software limitation of 1900RPM, so an increase of 37%. Setting the 'forced' key back to 0 successfully restored default operation.
@bmacphail Your site is dead, do you happen to have a mirror of the article? I just recently mistyped a digit and similarly found out that you can exceed the standard 6100 RPM on a macbook pro, which I thought was interesting, and wanted to learn more.
My experience with a mac pro 2013: it’s an artificial limit to keep the noise down. The computer will actually raise the ‘maximum’ according to how hot the cpu is. Whether this is true for laptops as well I don’t know, but I’d guess it is.
Also, although you tamper at your own risk, as they said above the fans are usually rated for 12V and limited by the 12V power supply. That should mean it’s safe to set the limit to whatever. For my mac pro, the artificial limit is 1900rpm. The real limit is around 2600rpm. You could set the target speed to 5000 and it would just sit happily at 2600 because it’s already supplying 12V.
I finally found the blog post at https://s3.ca-central-1.amazonaws.com/stuff.benmacphail.ca/how-to-make-a-jet-engine-from-scratch.html, redirected from https://blog.bnjmn.id/2022/04/25/if-you-are.html
That was insanely hard to find.... a redirect would have been easier imo.