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

[mj_]

This has been an ongoing issue with MacBook Pros for many years now. I've seen the exact same behavior on my 2015 15" with dGPU: as soon as I plugged in the external 27" 4K display the fans went completely bonkers regardless of resolution. The difference between both internal and external on scaled resolutions and internal and external on "Optimal for Retina" (aka Default for Display) resolutions was negligible. The MacBook Pro became noticeably quieter in clamshell mode but still far from acceptable. If, however, you plug in a LowDPI non-Retina screen, such as a 32" Ultrawide, it remains cool and quiet. I'm really disappointed to see this is still an issue in late 2019.

Op, you could try one thing to verify this: open system preferences, go to Displays, then hold down the Option key while klicking on "Scaled". This should give you various resolutions to pick from. Now enable the "Show low resolution modes" option, which will give you LowDPI as well as HiDPI resolutions. Pick the corresponding low resolution to your current HiDPI resolution, e.g. 1920 x 1080 (low resolution) or 2560 x 1440 (low resolution). Image quality is going to be abysmal but that way you'll be driving your external display in LowDPI instead of HiDPI mode and should be able to notice a significant decrease in fan noise within a few minutes if not seconds.

 

[Appledoesnotlisten]

This has been an ongoing issue with MacBook Pros for many years now. I've seen the exact same behavior on my 2015 15" with dGPU: as soon as I plugged in the external 27" 4K display the fans went completely bonkers regardless of resolution. The difference between both internal and external on scaled resolutions and internal and external on "Optimal for Retina" (aka Default for Display) resolutions was negligible. The MacBook Pro became noticeably quieter in clamshell mode but still far from acceptable. If, however, you plug in a LowDPI non-Retina screen, such as a 32" Ultrawide, it remains cool and quiet. I'm really disappointed to see this is still an issue in late 2019.

Op, you could try one thing to verify this: open system preferences, go to Displays, then hold down the Option key while klicking on "Scaled". This should give you various resolutions to pick from. Now enable the "Show low resolution modes" option, which will give you LowDPI as well as HiDPI resolutions. Pick the corresponding low resolution to your current HiDPI resolution, e.g. 1920 x 1080 (low resolution) or 2560 x 1440 (low resolution). Image quality is going to be abysmal but that way you'll be driving your external display in LowDPI instead of HiDPI mode and should be able to notice a significant decrease in fan noise within a few minutes if not seconds.

You are correct.

However... this article claims that the 16" can power these setups without any problem:

• Two LG UltraFine 5K displays configured at 5,120 x 2,880 10bpc at 60Hz
• Four LG UltraFine 4K displays configured at 4,096 x 2,304 8bpc at 60Hz
• One LG UltraFine 5K display connected to one side of your Mac and two LG UltraFine 4K displays connected to ports on the opposite side

How hot will it all be?

MacBook Pro 16-inch is powerful enough to drive two 6K monitors

Can cope with a pair of Apple’s Pro Display XDR monitors (when they’re out)

www.techradar.com

 

[nudoru]

External 4k monitor here and I don't notice anything when I connect it to my 16".

 

[chrizzz09]

Why are you running your external monitor only at a refresh rate of 30Hz?

Try changing your display cable to one that supports 4k/60Hz and see how it runs. It should stay quiet and temps should be around 50-60C.

I run a 2018 6-core/560X with a 4K Dell monitor and it runs just fine and fans are at the idle speed of ~2000rpm most of the time.

 

[Appledoesnotlisten]

Guys what resolutions are you running on both screens?

 

[chrizzz09]

Both at standard retina/best for monitor setting:

Internal at 3360 x 2100 (UI looks like 1650 x 1050 HDPI)
External at 3840 x 2160 (UI looks like 1920 x 1080 HDPI)

 

[Cape Dave]

Easy answer. Rest the unit on a block of ice when using external monitor. Issue solved! For extra points, put a thin fan on top of that ice blowing upwards first.

 

[Speedies]

Having had a somewhat similar experience, I thought I'd way in on this topic.

I picked up a base 16 inch machine on Sunday and experienced awful temperatures and fan noise. I would boot the machine after setting it up and it would be at 90 degrees and the fan going nuts. Lets not even talk about the jet engine that arrived in my room when I plugged it into my 3440x1440 ultrawide...

So on Monday I took it back and explained my problem and in fantastic apple fashion they no questions asked (didnt even look at the conidition of the machine, though it was perfect) swapped it out and apologised.

I've had this new machine for a couple of days now and it is WAY quieter than the last one but the way the fans and temperaturs come on is the same, just way cooler and queiter. So with just the internal display the laptop is around 45-55 degrees doing some 8 tab web browsing, whilst staying silent.

Then with JUST the external monitor on (likely because its forcing the dedicated graphics to come on) the temps are 60-67 average with a twitch stream running at source quality. Still silent to very quiet here.

Now the interesting part, when running both the external display and retina display, the fans jump up to around 3500rpm to keep the temps between 60-70 degrees. Its not loud by any means, but noticeable.

So my conclusion from this is the first one I had was a complete DUD, literally when they wiped it in the store it bootlooped for 15 minutes straight before they claimed it dead.

The second one, if we assume the hardware is functioning as expected which it seems to be, gets audible only when running both displays or heavy workloads. If we also consider that apparently this generations macbook pro has louder fans than the previous, this seems to be the situation for running external displays on the base 16 inch.

Key thing for OP would be clean installing the machine I think, checking if the temps are still hitting 90s doing not much and if they are, get it checked out with Apple - might be a DUD. Good luck.

 

[TimothyB]

As promised, I installed iStat Menu. Barely got to this today as I ended up sick and had trouble focusing on anything.

So, in the attached image, I basically progressed through some simple 5 minute tests with a few notes.

Edit: This is also after updating to macOS Catalina 10.15.1

Edit 2: I mistakenly had the external monitor scaled at 3200x1333 instead of running native 3840x1600

Click to see full-size:



External Display:

• LG 38" 38UC99-W
• Set to 3840x1600 (native resolution) - Scaled to look like 3200x1333, because I forgot to check.
• USB-C Connection, which provides 60 watts to MacBook.

 

[maik_is_here]

As promised, I installed iStat Menu. Barely got to this today as I ended up sick and had trouble focusing on anything.

So, in the attached image, I basically progressed through some simple 5 minute tests with a few notes.

Edit: This is also after updating to macOS Catalina 10.15.1

Edit 2: I mistakenly had the external monitor scaled at 3200x1333 instead of running native 3840x1600

Click to see full-size:
View attachment 878144


External Display:

• LG 38" 38UC99-W
• Set to 3840x1600 (native resolution) - Scaled to look like 3200x1333, because I forgot to check.
• USB-C Connection, which provides 60 watts to MacBook.

can you please install intel power gadget? It will allow you to view processor frequency in istat. I would be dying to know what frequency your machine can hold after being on full load for a few min while on multiple monitors

 

[An-apple-a-day]

This is what I was afraid of. It made me return a 15” because of it. I suspect it’s even worse if you use a scaled mode on a4K monitor like I do too. Those temperatures don’t come down after a while. Your istats menu is showing it idling but you are at 90+ degrees?!

Use "default for display" (or whatever it says) setting for the external 4K. On my 2016 15", "scaled" makes the machine get way hotter. But if I really want the higher res, I live with it. When mine is connected to an external 4K monitor on my desk, the MBP sits on a solid aluminum stand causing it to be elevated and tilted forward. Then I use my external magic keyboard and magic trackpad, of course. It seems to help a lot with the cooling. It also minimizes risk of damage from spills, etc.

I really wish Apple wouldn't engage the dGPU automatically when connecting an external monitor (I'd much prefer a changeable preference for that). The built-in Intel graphics is more than powerful enough to drive the external 4K for my modest S/W development needs.

As somebody had mentioned, the 16" probably has much improved thermals (I don't have one -- yet) but that just raises the performance ceiling if you're putting demands on it (CPU, GPU and esp. both simultaneously). Nonetheless, I'd bet that the 16" would be cooler and running with less fan noise in my particular environment, though. The recent 15" versions with Vega graphics run way cooler than the equivalent configurations without Vega. I'd suspect the same to be true for the Navi 7nm 5300/5500M.

 

[grmlin]

I just want to say: I'm really disappointed that this is still an issue. I had some hope that a new GPU architecture will fixes things.

I use my 2019 MBP 15" connected to a 4K screen every day, and it gets way too hot. Fans are kicking in all the time, and I would never close this MBP and use it in clamshell mode. I'm afraid it can't be healthy for the hardware.
I used a 15" from 2014 before, and even that thing didn't get as hot as the new one.

The WindowsServer never drops below 30-40% I would say, and the UI is stuttering all the time. It's not as bad as with my old machine, but still never fluid.

Things get better when I use the display in it's recommended non scaled resolutions, but it's still terrible.


At first I was hyped for the 16", but in the end it has the same issues, as it's the same MacOS.

 

[Kraizelburg]

I just want to say: I'm really disappointed that this is still an issue. I had some hope that a new GPU architecture will fixes things.

I use my 2019 MBP 15" connected to a 4K screen every day, and it gets way too hot. Fans are kicking in all the time, and I would never close this MBP and use it in clamshell mode. I'm afraid it can't be healthy for the hardware.
I used a 15" from 2014 before, and even that thing didn't get as hot as the new one.

The WindowsServer never drops below 30-40% I would say, and the UI is stuttering all the time. It's not as bad as with my old machine, but still never fluid.

Things get better when I use the display in it's recommended non scaled resolutions, but it's still terrible.


At first I was hyped for the 16", but in the end it has the same issues, as it's the same MacOS.

Problem isn't GPU nor CPU but how thin and not enough cooling this laptops have. If you do the same test plugged to an external 4k monitor with a proper thick gaming laptop it won't get as hot. Nevertheless laptops no matter what will always get way hotter than a proper PC, imac etc, you name it with good cooling.

I own a MBP and a ryzen 6 cores PC with nvidia 1070 and it never get hotter than 60ºC.

So the moral is we get as much performance as we can for such a thin chassis, high Temps are the price to pay.

 

[An-apple-a-day]

I just want to say: I'm really disappointed that this is still an issue. I had some hope that a new GPU architecture will fixes things.

I use my 2019 MBP 15" connected to a 4K screen every day, and it gets way too hot. Fans are kicking in all the time, and I would never close this MBP and use it in clamshell mode. I'm afraid it can't be healthy for the hardware.
I used a 15" from 2014 before, and even that thing didn't get as hot as the new one.

The WindowsServer never drops below 30-40% I would say, and the UI is stuttering all the time. It's not as bad as with my old machine, but still never fluid.

Things get better when I use the display in it's recommended non scaled resolutions, but it's still terrible.


At first I was hyped for the 16", but in the end it has the same issues, as it's the same MacOS.

How is your external 4K connected? Via a USB-C to DisplayPort connector, I'd assume. That's how mine is connected. In scaled mode, for example, with 3D animated graphs, a video playing on the external monitor (and Activity Monitor itself -- with no display state change occurring on built-in display), my 2016 15" Radeon Pro 460 (Mojave) shows WindowServer @20%. At default for display, it's also around 20% but runs cooler (GPU working less?). No fans audible so far... after at least an hour.

 

[Kraizelburg]

Via a USB-C to DisplayPort connector, I'd assume.

I have mine connected USB-C to USB-C, unless you dont have an USB-C monitor which I doubt there is no point using DP.

Most monitors since 2016 have USB-C as well as DP, HDMI, etc

 

[grmlin]

Problem isn't GPU nor CPU but how thin and not enough cooling this laptops have. If you do the same test plugged to an external 4k monitor with a proper thick gaming laptop it won't get as hot. Nevertheless laptops no matter what will always get way hotter than a proper PC, imac etc, you name it with good cooling.

I own a MBP and a ryzen 6 cores PC with nvidia 1070 and it never get hotter than 60ºC.

So the moral is we get as much performance as we can for such a thin chassis, high Temps are the price to pay.

Oh, of course. My problem is not so much the fan noise, but the performance. AFAIK even thick mobile workstations like Lenovos new P53 also get loud when you push them.

How is your external 4K connected? Via a USB-C to DisplayPort connector, I'd assume. That's how mine is connected. In scaled mode, for example, with 3D animated graphs, a video playing on the external monitor (and Activity Monitor itself -- with no display state change occurring on built-in display), my 2016 15" Radeon Pro 460 (Mojave) shows WindowServer @20%. At default for display, it's also around 20% but runs cooler (GPU working less?).

why would that make any difference? Just curious. I'm using a caldigit dock in the office, and an USB-C –> HDMI cable at home.
I'm pretty sure the issues are caused by the software I use. My IDE for example is Java based, and that's not the greatest fit for MacOS?
My MBP is dead silent not connected to a display doing nothing. Light office work is ok, too. Opening Twitch streams for example will always trigger the fans. No matter if it's connected to an external monitor or not.

 

[Kraizelburg]

Opening Twitch streams for example will always trigger the fans. No matter if it's connected to an external monitor or not.

Uhmmm that sounds strange, I can watch twitch and youtube playing and fans don't even kick in. Maybe fan curve in the 16" is tweaked...? Dunno to be honest.

 

[grmlin]

Uhmmm that sounds strange, I can watch twitch and youtube playing and fans don't even kick in. Maybe fan curve in the 16" is tweaked...? Dunno to be honest.

The 16" supposedly has better thermals, so thats good to hear. The problem is that this is not how I use the machine.
Good, I would love to test a linux laptop for a month and see if it's any better than a Mac or the same in the end. I'm pretty sure the grass is only greener on the other side as long as I'm not standing on it...

I used my pretty old desktop at home with a boring i5 with 4 cores with linux for some weeks, and it was a night and day difference. My colleague with an iMac from 2016 (I think) does not have any problems either. I think it's just the nature of a laptop.

 

[Kraizelburg]

The 16" supposedly has better thermals, so thats good to hear. The problem is that this is not how I use the machine.
Good, I would love to test a linux laptop for a month and see if it's any better than a Mac or the same in the end. I'm pretty sure the grass is only greener on the other side as long as I'm not standing on it...

I used my pretty old desktop at home with a boring i5 with 4 cores with linux for some weeks, and it was a night and day difference. My colleague with an iMac from 2016 (I think) does not have any problems either. I think it's just the nature of a laptop.

I was talking about my 13" MBP I don't own a 16". My believe is that this i9 are very power hungry and it's still coffee lake 14nm+++. I guess we can't ask for more with such a thin chassis.

 

[grmlin]

Oh, I see. As an example: My timemachine backup is running in the background right now (preparing the backup) and the CPU sits at 80º C constantly, running at around 3 GHz. No wonder it's hot.

 

[An-apple-a-day]

Oh, of course. My problem is not so much the fan noise, but the performance. AFAIK even thick mobile workstations like Lenovos new P53 also get loud when you push them.




why would that make any difference? Just curious. I'm using a caldigit dock in the office, and an USB-C –> HDMI cable at home.
I'm pretty sure the issues are caused by the software I use. My IDE for example is Java based, and that's not the greatest fit for MacOS?
My MBP is dead silent not connected to a display doing nothing. Light office work is ok, too. Opening Twitch streams for example will always trigger the fans. No matter if it's connected to an external monitor or not.

Not sure why, but based on some coworkers' experiences (anecdotal evidence), there was a difference. They have 4K monitors capable of both HDMI and DisplayPort connections. They initially had connected their 2016/2017 MBP 15's via USB-C to HDMI adapters (cuz they thought HDMI was somehow better). I told them to ditch those and switch to USB-C to DisplayPort cables. Their machines ran cooler and display quality was better (refresh rate was 60Hz vs. 30 and image seemed clearer). I know HDMI and DisplayPort are doing the leapfrog game (and I think HDMI can do the 60Hz for 4K these days), but unless you have some dedicated A/V equipment you're connecting to, DisplayPort is superior for a variety of reasons.

 

[grmlin]

My HDMI connection at home runs at 60Hz, of course. In the office I use displayport, and it makes no difference at all.

Older MacBooks didn't support HDMI 2.0 (or whatever version it is that can do 4K @ 60Hz), but every MBP since 2016 does afaik.

 

[wesStyle]

As promised, I installed iStat Menu. Barely got to this today as I ended up sick and had trouble focusing on anything.

So, in the attached image, I basically progressed through some simple 5 minute tests with a few notes.

Edit: This is also after updating to macOS Catalina 10.15.1

Edit 2: I mistakenly had the external monitor scaled at 3200x1333 instead of running native 3840x1600

Click to see full-size:
View attachment 878144


External Display:

• LG 38" 38UC99-W
• Set to 3840x1600 (native resolution) - Scaled to look like 3200x1333, because I forgot to check.
• USB-C Connection, which provides 60 watts to MacBook.

Thanks! Have you tried also closing the lid when connected to the external display?​

Can you please also enable gpu icon in the settings and check its dropdown? I'd really like to see how the new gpu performs frequency/power-wise with different display configurations compared to 15". And you can also see which gpu is activated at the moment there.​

 

[x-evil-x]

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 2017 version in this respects.

Can you guys share your thoughts on this?

Thanks a lot!

do you run your lid closed or open? Same issue I've had on my 2016 and 2019. In closed lid the computer gets too hot. I leave it cracked 25% open now.

 

[ascender]

I've left the 4K connected at its highest resolution for the last day and I'm really not noticing any negative effects. The laptop isn't in clamshell mode however and I've not gone as far as installing iStat menus because nothing seems amiss.