How to turn off Turbo Boost temporarily?

Question

In our application we have many versions of the same routine optimized for different kind of processor architectures. During install we run performance tests and select the best version of routine.

Latest processors can boost their frequencies if few cores are in use, so sometimes our tests peeking wrong version of routine. Is there some way to temporarily turn off Turbo Boost?

Did you ever find a solution for this ? I'd like to be able to turn off Turbo Boost on a Mac, so that I can do reliable benchmarking during code optimisation etc. I don't even mind if I have to reboot to achieve this, but it doesn't seem possible, unlike on a PC, where you can do it via a BIOS setting. — Paul R, Mar 03 '11 at 08:53
@Paul R: nope. I spent two days googling, and decided to leave it as it is. — actual, Mar 05 '11 at 14:32
it seems that the best you can do at the moment is disable it in the BIOS if you have PC hardware, but on a Mac you're out of luck. There does seem to be a possibility of hacking rEFITt to do it, but I don't have time to investigate this just now. — Paul R, Mar 05 '11 at 14:51

score 2 · Answer 1 · answered Apr 29 '10 at 14:02

2

I don't know the opcode for enabling/disabling turbo boost directly, but apparently it's possible because TMonitor - which is a Windows application - can do it at runtime.

answered Apr 29 '10 at 14:02

pi.

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Nice utility, but Turbo Boost toggle doesn't do the work, at least on my laptop. – actual Apr 29 '10 at 19:09
Can anyone confirm that TMonitor can toggle Turbo Boost in Windows? – netvope Jun 23 '11 at 05:59

score 2 · Answer 2 · edited May 23 '17 at 11:46

There are MSR registers (https://en.wikipedia.org/wiki/Model-specific_register) in Intel CPUs to disable/enable per-core turbo boost. In linux, there are msr-tools package which allow root to read/write to MSR registers. There are two posts about Turbo Boost disabling/enabling in Linux:

https://askubuntu.com/questions/619875/disabling-intel-turbo-boost-in-ubuntu "Disabling Intel Turbo Boost in ubuntu", answer by Maythux from 2015

http://luisjdominguezp.tumblr.com/post/19610447111/disabling-turbo-boost-in-linux Disabling Turbo Boost in Linux, Luis J. Dominguez P, 2012-2013; Sandy Bridge - "38th bit of the 0x1a0 register."

http://notepad2.blogspot.com/2014/11/a-script-to-turn-off-intel-cpu-turbo.html

And there is kext for OSX to do the same: Disable Turbo Boost on Core i7 Mac?

score -1 · Answer 3 · answered Jan 08 '20 at 18:45

In windows OS you can add the following reg key.

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\PowerSettings\54533251-82be-4824-96c1-47b60b740d00\be337238-0d82-4146-a960-4f3749d470c7]
"Attributes"=dword:00000002

Then in advanced power settings you will get new option that allows you turning off turbo boost.

How to turn off Turbo Boost temporarily?

3 Answers3

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