Re:If a MacBook Pro runs hot or shows high kernel CPU, try c...
by magicalhippo on Thursday April 23, 2020 @04:40PM
(#22961070)
> Unfortunately, some conditions force the discrete GPU to activate - one of which is "being plugged into an external monitor."
Had something similar with AMD (desktop) GPU some years ago. It wouldn't go to the lower power states if my desktop refresh rate was set above 119 Hz. So it would be hot and fairly loud. So I ended up using 119 Hz on the desktop and configure games to use 144 Hz.
I also noticed that the video card wouldn't decrease the RAM clock rate significantly, but when on the desktop reducing the RAM clock a lot had a very noticeable impact on heat and no measurable performance degradation. The answer I got for that was that it was tricky to dynamically scale the RAM to such a degree (IIRC I set it to half normal speed). I ended up using an overclocking tool with profiles, worked fine.
Had something similar with AMD (desktop) GPU some years ago. It wouldn't go to the lower power states if my desktop refresh rate was set above 119 Hz. So it would be hot and fairly loud. So I ended up using 119 Hz on the desktop and configure games to use 144 Hz.
I also noticed that the video card wouldn't decrease the RAM clock rate significantly, but when on the desktop reducing the RAM clock a lot had a very noticeable impact on heat and no measurable performance degradation. The answer I got for that was that it was tricky to dynamically scale the RAM to such a degree (IIRC I set it to half normal speed). I ended up using an overclocking tool with profiles, worked fine.