Looking into a mainboard w/AI 9 HX 370. I know this CPU has hybrid cores (4x performance & 8x efficiency). Trying to build a low powered handheld (relying on batteries). Can I disable the “performance” core in BIOS (to force OS and app to only use efficiency cores). I know scripting CPU affinity works most times, but I would rather not rely on a script. Anyone knows if BIOS settings exist in Framework laptops?
On Linux, you can take CPUs offline. I don’t know if it saves power or not. Give it a try.
Take it offline:
sudo echo 0 > /sys/devices/system/cpu/cpu1/online
Put in online:
sudo echo 1 > /sys/devices/system/cpu/cpu1/online
Change “cpu1” to your needs.
I don’t think is a good idea to get a high performance mainboard and shutdown the CPU cores. The P/E cores allocate power automatically according to your load as long as you have the kernel and driver installed correctly. Manually disabling cores can make your computer less energy efficient. If you aren’t going to use that much performance why not buy a cheaper mainboard such as the 7640U or the Ultra 5 125H?
You won’t be able to offline all the performance cores. The BSP is the first core and the kernel doesn’t let you take this one offline.
Nice, didn’t know the importance of core 0. I’ll learn a new CPU affinity script for Linux. I regularly use a PowerShell script for Windows (only software that rejects affinity are AnTi-ChEaT gAmEs).
For Charlie_6, I want the 890M iGPU (the Arc B390 is appealing but the CPU has so many odd hybrid cores)
Are you sure disabling cores is even helping efficiency? Above minimum load having more cores running slower tends to use less powers than fewer running faster.
The full fat non-e cores here are also not necessarily worse at power efficiency than the e ones. The efficiency in that generation of e-cores is more about die space efficiency and not being able to clock as high. Clock for clock there isn’t a huge power difference and also not always in the same direction.
I am looking forward to zen6 which apparently will get actual power efficiency cores where they trade space efficiency and max clocks for better power efficiency, very curious how that’ll work out.