I've been running a 31.5" QHD display for a few months with my 10th gen MBP 13" and it has been awesome. Average CPU temps have been in the high 30C range for the most part and all was well.
After reading a bunch of stuff about subpixel-AA and font rendering issues since Mojave and what frou said, I decided to see what an LG 21.5" UltraFine 4K (22md4ka) display looked like. Wow- it is super sharp and text is large enough for me in default for display vs scaled mode.
One thing I figured out very quickly is that a longer/thinner Thunderbolt cable (from my HP QHD display) was having issues after ~10 minutes of being connected to the LG 4k display.
Both my MBP screen and the LG 4k external display were going black and powering back up every 2-3 minutes and the average CPU went up from ~40C to steady above 60C or more. When I attached the Apple power supply to another port on the MBP, it stopped happening for a short period of time (after reboot) and then started up again. I did a PRAM reset and screen blanking continued every few minutes.
I suspected that the cable was either too long or could not quite push enough wattage. The other telltale sign was when I cranked up the volume playing Miserlou on iTunes, the sound coming out of the LG display speakers was very choppy/distorted.
I installed a shorter/thicker/100W-rated Belkin .5M Thunderbolt 3 5K cable and all is well on battery or attached to the Apple power adapter. MBP temps are back around 42C as well.
After reading a bunch of stuff about subpixel-AA and font rendering issues since Mojave and what frou said, I decided to see what an LG 21.5" UltraFine 4K (22md4ka) display looked like. Wow- it is super sharp and text is large enough for me in default for display vs scaled mode.
One thing I figured out very quickly is that a longer/thinner Thunderbolt cable (from my HP QHD display) was having issues after ~10 minutes of being connected to the LG 4k display.
Both my MBP screen and the LG 4k external display were going black and powering back up every 2-3 minutes and the average CPU went up from ~40C to steady above 60C or more. When I attached the Apple power supply to another port on the MBP, it stopped happening for a short period of time (after reboot) and then started up again. I did a PRAM reset and screen blanking continued every few minutes.
I suspected that the cable was either too long or could not quite push enough wattage. The other telltale sign was when I cranked up the volume playing Miserlou on iTunes, the sound coming out of the LG display speakers was very choppy/distorted.
I installed a shorter/thicker/100W-rated Belkin .5M Thunderbolt 3 5K cable and all is well on battery or attached to the Apple power adapter. MBP temps are back around 42C as well.
