Q: External display over HDMI overheats my Mac and drains battery badly
Hey guys.
I've been using a 15-inch MBP Retina 2012 with an external display, a generic 1080p LCD via HDMI, without problems. And recently upgraded to Sierra.
The issue immediately starts when I'm plugging in the display. The Macbook seems to overheat and runs its fans above 4000rpm, which is very audible and annoying. The CPU and GPU temperatures go above 70 degrees C (normally they do 50+). The battery holds for only 1.5 hours, usually working fine for 4-5 hours.
I tried killing all apps, tracking a bad proccess in Activity Monitor, switching to default resolution — nothing helps so far. The CPU is barely used by 10%, the memory pressure is fine.
It's just that moment when I plug the monitor — the Mac starts feeling bad. The problem never occured on El Capitan. Maybe it's some GPU problem, but definitely OS-caused.
Has anybody had the same issue?
MacBook Pro with Retina display, macOS Sierra (10.12), External Display
Posted on Sep 27, 2016 2:47 AM
Try resetting NVRAM (hold down command-option-P-R at startup).
Also, try restarting in Safe Mode and then normally again.
Finally, try logging out of your normal account, log in to a new user account (or the guest account), and connect the external display. Same problem? If it works fine for a new account then it is something in your own account that is causing it - possibly a login item or some other system modification carried over from the previous OS and that is not playing nice with Sierra.
Posted on Sep 27, 2016 4:06 AM