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macrumors newbie
Original poster
Mar 9, 2020
Manchester, United Kingdom.
Hi there,

Just picked up a brand new 2019 15" MBP, and a couple of times now it has overheated. I have toggled on and off the automatic graphics switching depending on the task at the time, and I use the laptop with 2 monitors via USB-c sat on an extended mouse mat.

This has now also happened with the laptop not plugged into anything. This seems to happen more than it did on my Early 2015 model.

So far, I have not noticed a drop-off in performance. Is this a known issue, if so is there a resolution.


macrumors member
Apr 22, 2012
I was just about to post about my 2019 13", I think it is to do with external monitors. I currently have mine connected to a Targus USB C dock, with two HP monitors, at home I have a 4K LG. When connected to either of them, the body gets hot and I'm having to use an external keyboard.

I haven't had any temperature warnings but it's uncomfortable to use.

Have looked at Activity Monitor and nothing is out of the ordinary, have installed iStat most sensors are around 60 degrees celsius when it gets hot, palm rest sensor gets up to about 35 deg. If I use iStat to increase the fan speed I can cool it down, but leaving Mac OS to handle it, the fan seems to barely run even though I find it hot!


macrumors 6502
Jun 11, 2013
If the laptop doesn't switch off by itself to prevent damage due to heat, it does not overheat. CPU temps can reach up to 100 degrees Celsius and that's normal. There are safeguards preventing any damage from higher temps, usually by throttling the CPU.
You feel the case to be hot because of the aluminium being a good head conductor removing heat from the insides. Usually this happens when the computer is in high load. External monitors always use the dGPU and this heats it up.
Also the chassis is tinnier than a 2015 model so less air is circulating inside and also there is a higher CPU core amount (8 vs 4).
But if you believe this shouldn't be happening, check activity monitor for any apps or processes that use the CPU excessively with out reason. Note that when you first start using a new mac and installing software, OS indexes files and uses a big chuck of power.


macrumors newbie
Original poster
Mar 9, 2020
Manchester, United Kingdom.
Just picked up a 15 incher?

Return it. Get the 16". Issue fixed. No overheating problems with better cooling components and design.

I debated getting the 16-inch but I wanted the butterfly keyboard switches. Unpopular opinion I know but I hated the keys on my 2015 retina. Plus a got a great deal from Costco so it was a no brainer
RESOLVED: This was an issue due to a really strenuous workload (3 creative cloud apps being used at the same time, paired with using 2 monitors wired straight into the Mac. I am now using temp monitor to keep an eye on things and manually increase the fan speed to keep the cpu cool before it gets too hot.


macrumors newbie
Dec 23, 2020
For what it's worth, I have a similar problem on the 2019 MBP 16" laptop.

Intermittently, the laptop temp skyrockets from normal temps (55–60 C / 130–140 F on CPU Core 1 temp sensor) to absurdly high temps (75 C / 167 F) that make the laptop painful to the touch in the area near the speaker vents and especially so above the menu bar (above the control strip). Simultaneously, during those heat spikes, I have noticeable degradation of performance.

This is regardless of my usage habits or apps I have open.

I noticed the heat issue when I first set up the laptop (bought brand new), but I thought it might just be some background processes with caching/cleanup or whatever other things happen in the background when setting up a new computer. But, this remains to be an issue.

It's unpredictable. Occasionally, I've returned home to find it in the middle of a "heat flash". Other times, it will go for hours with no problem. It happens whether it's plugged in or not.

  • Overview
    • macOS Catalina version 10.15.7
    • 2.4 GHz 8-Core Intel Core I9
    • 64 GB 2667 MHz DDR4
    • AMD Radeon Pro 5500M 8GB
    • Intel UHD Graphics 630 1536MB
  • Display
    • 16-inch display (3072 x 1920)
    • AMD Radeon Pro 5500M 8GB
Typical usage
  • Plugged in (via CalDigit TS3 Plus) that has some accessories connected to it:
    • Some midi devices (turned off until needed)
    • 1 external hard drive, low RPM and separate power source
    • Sound mixer, also separate power source
  • Note that I've tried plugging charger in directly, without connecting the CalDigit TS3, but it didn't resolve the issue.
  • Wifi enabled
  • No external monitor, keyboard, or mouse
  • Propped up to permit airflow all around the laptop base
  • Laptop keyboard, lights at lowest setting while still being on
  • Display brightness typically 50–75%, leaning more toward 50%
  • App usage
    • During work:
      • 3 Safari windows with maybe 3-10 tabs each, varying throughout the day. Sites are typical for my role — gmail, calendar, one or two google documents/sheets, Jira, and some miscellaneous sites for research
      • Slack
      • Zoom (main app open, occasionally have a call, and occasionally share screen/video during the call)
      • Occasionally Figma, but only when needed
    • When not working:
      • Only Ableton open, everything else closed
      • Or, Discord + a few Safari windows
    • Only one user logged in at a time
What I've done so far
  • Checked activity monitor duding these points in time.
    • WindowServer seems to consistently have a surprisingly high %CPU (i.e., I wouldn't expect window server to be >20% when only activity monitor is open, and I see it go well over 100% during the heat spikes).
  • Turned off automatic graphics switching.
    • No effect, symptom persists
  • Turned off transparency.
    • No effect, symptom persists
  • Checked contents of /Library/LaunchAgents AND ~/Library/LaunchAgents
    • Adobe Creative Cloud
    • A license service (iLOK) for audio plugins that I use on Ableton
    • Paragon software notification agent (supports NTFS for Mac)
    • Nothing suspicious
  • Checked contents of ~/Library/Application Support
    • Nothing suspicious
  • Checked contents of /Library/LaunchDaemons
    • Nothing suspicious
  • Checked all applications, nothing out of the ordinary
  • Checked Preferences > Users > (each user) > Login Items
    • Very few items here
    • Nothing suspicious
  • Cleared all caches/history/etc from Safari
    • No effect, symptom persists
I'm at a loss. The intermittent heat spikes (and corresponding performance degradation) are particularly a nuisance when creating music. Despite being the primary driver behind my purchase, I wouldn't trust this device in a live music performance setting.

I'm disappointed, to say the least.
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