Comparing 13" to 16": Increase in core temperature when adding 4K monitor

[iRun26.2]

On this forum I've read about some people considering moving from the 2019 16" to the 2020 13" just to reduce the temperature / fan speed when using an external monitor (not in 'clamshell' mode). I temporarily have both in my possession so I decided to do a test related to this topic:

1) I Charged up both computer's batteries, exited all programs (just the Finder was open), and put them to sleep for a while to let them cool.
2) I then took them out of sleep, having them active using only the built in display for roughly 10 minutes (computer doing nothing, just 'on').
3) I used iStat Menus to measure the core temperature (1st temperature below).
4) I then plugged in my 32" LG 4K monitor (set to full 4K resolution via scaling) leaving the built-in display on ('on' but unusable at 4K).
5) After another 10 minutes I again used iStat Menus to measure the (stabilized) new core temperature and also the fan speed.

This is what I found:

2020 13" 10th gen i7: 35C to 45C (fans reported 0 rpm)
2019 16" 9th gen i9: 39C to 65C (fans reported ~2000 rpm)

(I am keeping the 2020 13" 10th gen. i7 and sending back the 2019 16: 9th gen. i9)

 

[Alex W.]

yep I’ve mentioned this on apples fan noise thread but keep getting instantly nodded and censored, Apple is obviously trying to avoid a recall or major issue with this 16”

 

[Anonymous Freak]

I have three 4K monitors plugged in to my 16", no problems.

 

[iRun26.2]

I have three 4K monitors plugged in to my 16", no problems.

How much warmer is the machine when you plug all three of them in?

 

[bomby0]

Yeesh that temperature difference is dramatic. Thanks for the side by side testing!

That dGPU is really screwing things up for people who use external monitors.

 

[Anonymous Freak]

How much warmer is the machine when you plug all three of them in?

It definitely runs a little warmer, but not so much that the fans are audible. (At least in standard "desktop application" use. Obviously things like games or video editing spike, but they'd do that even with just the internal display.) I'll do some more scientific-like testing this evening.

 

[iRun26.2]

It definitely runs a little warmer, but not so much that the fans are audible. (At least in standard "desktop application" use. Obviously things like games or video editing spike, but they'd do that even with just the internal display.) I'll do some more scientific-like testing this evening.

Do you have iStat Menus? I’d really like to know the temperature.

 

[Grohowiak]

Have fun:

(2019) 16" is HOT & NOISY with an external monitor! :(

I received a base 16" today and am disappointed because it get's as hot as my 2017 with an external 4K monitor. Is anybody else experiencing the same issue? I always work with external monitors and running on high resolution and this heating performance is upsetting. It's not cooler than the...

forums.macrumors.com

 

[Quackington]

yep I’ve mentioned this on apples fan noise thread but keep getting instantly nodded and censored, Apple is obviously trying to avoid a recall or major issue with this 16”

Wait, Apple is censoring you on their forum for posting about this issue?

 

[Anonymous Freak]

Do you have iStat Menus? I’d really like to know the temperature.

That's what I use.

Oh, hey, look, I responded in the thread Grohowiak linked:

16" is HOT & NOISY with an external monitor! :(

Haven't had that problem with mine. But mine's an upgraded model - Core i9, 32 GB RAM, and Radeon 5500M 8 GB. I run three 4K displays plus the internal - (all at not-200%-scaling, thus more-GPU-intensive.) No massive CPU or GPU load, fans stay quiet. (Playing a 4K YouTube video while this...

forums.macrumors.com

 

[iRun26.2]

Have fun:

(2019) 16" is HOT & NOISY with an external monitor! :(

I received a base 16" today and am disappointed because it get's as hot as my 2017 with an external 4K monitor. Is anybody else experiencing the same issue? I always work with external monitors and running on high resolution and this heating performance is upsetting. It's not cooler than the...

forums.macrumors.com

Like I could have possibly missed that thread on this forum! It can be overwhelming...

This is one instance where the integrate (Intel) graphics has a positive advantage (one of the reasons I chose the 13" over the 16").

 

[Anonymous Freak]

Do you have iStat Menus? I’d really like to know the temperature.

Here you go, at idle, CPU 70°C, GPU 68°C, fans at 1800ish RPM, in lid-closed mode, with three 4K/60 displays at non-2x scaling. (which is more GPU-intensive than operating at "Default" which is "Looks like 1920x1080" exact integer scaling.)

This is my normal. Lid-open temps and fans are slightly lower due to better airflow, even though there's then a fourth display operating.

Heck, while typing this, temps have dropped to 65°F CPU/63°F GPU, although fans spun up to barely-audible 2500 RPM.

 

[applesed]

Here you go, at idle, CPU 70°C, GPU 68°C, fans at 1800ish RPM, in lid-closed mode, with three 4K/60 displays at non-2x scaling. (which is more GPU-intensive than operating at "Default" which is "Looks like 1920x1080" exact integer scaling.)

This is my normal. Lid-open temps and fans are slightly lower due to better airflow, even though there's then a fourth display operating.

Heck, while typing this, temps have dropped to 65°F CPU/63°F GPU, although fans spun up to barely-audible 2500 RPM.

What type and vendor are the monitors?
With all this variation between temps I wonder if the monitor plays a role.

 

[magbarn]

Here you go, at idle, CPU 70°C, GPU 68°C, fans at 1800ish RPM, in lid-closed mode, with three 4K/60 displays at non-2x scaling. (which is more GPU-intensive than operating at "Default" which is "Looks like 1920x1080" exact integer scaling.)

This is my normal. Lid-open temps and fans are slightly lower due to better airflow, even though there's then a fourth display operating.

Heck, while typing this, temps have dropped to 65°F CPU/63°F GPU, although fans spun up to barely-audible 2500 RPM.

Your dgpu is pulling 21 watts in your pics. It’s not too bad if my room is cooled down to 70F and I’m not doing anything too intensive. The problem is using high powered apps and you’re already preheating the chassis with that stupid 18-21 watt gpu idle power usage while taking away heat and power budget from the cpu. If the drivers or hardware were working properly it should only be using 5-7 watts on idle like my MacBook Pro 15 does when hooked up to an external monitor.

 

[Fuchal]

It definitely runs a little warmer, but not so much that the fans are audible. (At least in standard "desktop application" use. Obviously things like games or video editing spike, but they'd do that even with just the internal display.) I'll do some more scientific-like testing this evening.

I see similar results. I run a 16" in clamshell mode with a 4K LG monitor and it runs considerably quieter than the 2015 15" it replaced.

 

[Anonymous Freak]

What type and vendor are the monitors?
With all this variation between temps I wonder if the monitor plays a role.

Brand of monitor shouldn't matter at all. They're all Samsung UE590 displays - one 24", two 28". Resolution and "looks like" setting are the important things. If you run them all in "native" - or "looks like" half their real resolution, it will be less GPU intensive than running it at non-native resolutions like I do.