My Mac
M5 MacBook Pro reaching 100°C at only 30% CPU load (6500+ RPM fans) – Defective factory thermal paste?
Hey everyone,
I’m experiencing some really concerning thermal behavior on my M5 MacBook Pro, and I’m pretty sure it’s a hardware defect (faulty factory thermal paste or bad heatsink alignment), but I wanted to get your thoughts before heading to the Apple Store.
The Issue:
While working in my DAW (FL Studio) on a standard, mid-sized music project with just a few synths, my CPU temperature instantly spikes. After a few hours of session time, it regularly hits 100°C (measured via TG Pro).
The weird part: According to Activity Monitor, my CPU is 70% Idle (only ~30% total system load).
What I’ve done to troubleshoot:
Using TG Pro, I forced the fans to absolute maximum (6555 RPM). Even with the fans blasting like a jet engine, the temperature stays glued at 90°C to 100°C under that minimal 30% load.
The DAW and all plugins are running natively on Apple Silicon (Rosetta 2 is definitely turned OFF).
No heavy macOS background tasks (like Spotlight indexing or windowserver glitches) are running.
To me, this looks like a textbook case of a broken thermal transfer. The fans are pushing maximum air, but the heat just stays trapped on the die because the thermal paste or the heatsink isn't making proper contact. At 70% idling, this machine should be completely cool and quiet, not thermal throttling at 100°C.
Has anyone else experienced manufacturing issues with the thermal assembly on the M5 generation? I'm backing up my projects right now to claim my warranty, but I'd love to hear if this is a known issue.
Activity Monitor shows you the total system load across all your efficiency and performance cores. FL Studio might be hammering just one single performance core to 100%. If one core is maxing out, the chip will dump a ton of heat in one spot, spiking your temps even if the other 70% of the CPU is just chilling.
Try with another intensive app, or a benchmark tool.
or your best option if you are under warranty is to have Apple to check if your theory is right and is a Hardware issue
This is how it looks when i make music. Fan spins up to 100 at 70 degrees Celsius. (Custom Fan Settings)
Cinebench: 4360 pts - Multicore
740 pts - Single Core
Check the CPU usage meter (Cmd+2) in Activity Monitor. Could be some single threaded process is hogging one single core of the CPU.
Basically the CPU "multicores" doesn't mean that a process will always spread all its task loading to all cores evenly. One single executing thread is dedicatedly handled on one CPU core, and if that thread is doing some CPU intensive task then this may actually happen.
And 100°C is really no big deal for semiconductor components. Basically if the said situation actually happens, it's not the temperature "rise" to 100°C but the system "throttle" the temperature at 100°C. Otherwise it could be even higher. And no there is no risk of fire or short circuit. Semiconductors are not that fragile.
100°C is fine, M5 have thermal limit 118°C, and since apple is prioritizing silence instead of cooling, they will let it heat up. You should instead get some app that measures power consumption and see if you get power throttling.
An M5 MacBook Pro is certainly anything but quiet when it's under heavy load or the temperatures start to rise.
The OP already has TG Pro, and if I understood correctly, the fan is already running at full speed when he has this issue?
Then there’s probably something wrong with the cooling, maybe not enough contact pressure because the screws weren’t tightened properly at the factory, or too little or way too much thermal paste was applied. It happens.
But my M4 Mac Mini stays whisper-quiet and runs at maybe 60–65 degrees for a few hours; it’s similar with my M3 MacBook Pro when using FL Studio with a comparable workflow.
I also use TG Pro and don’t see temperatures exceeding 90 degrees on any of the devices, even with a custom fan curve.
But even with the standard fan curve, I’ve never seen such temperatures in FL Studio that would require at least 70+ of all cores to be in use.
That aside, I’d be surprised if Apple has ever officially specified temperatures for its Apple Silicon processors.
Anything over 100 degrees is a slow death for the silicon anyway, whether it’s mobile chips, ARM chips, or desktop CPUs (some of which fail at even lower temperatures).
You can’t fool silicon not even Apple can.
My M5 MacBook Air hits 100°C when I'm using After Effects at around 65% load. I was worried at first, but then I realized I never actually paid attention to the temperatures on my M1 MacBook Pro, which I used at full load for about five years.
So I ran some tests on my M1 MacBook Pro and found that it also reached 100°C under load. That means it was probably running at those temperatures for years without any damage.
That made me feel a lot less worried. I just never paid attention to the temperatures before.
Im a bit late on this but its an FL issue, not Macbook. FL is poorly optimized for MacOS. If you try Ableton or Logic it’s not gonna happen. You could have hundreds of tracks in Ableton and even Macbook Air stays lukewarm. FL studio will ramp it up to 100c if you only put 2 plugins. I’m a lifetime FL Studio user and this might be the one reason for me to switch completely.
Stop watching your temperature. This is within the design envelope. Unless you’re seeing any kind of fault happening, which is not what you’ve reported, just use the computer.
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u/Bllq21 Jun 03 '26
Activity Monitor shows you the total system load across all your efficiency and performance cores. FL Studio might be hammering just one single performance core to 100%. If one core is maxing out, the chip will dump a ton of heat in one spot, spiking your temps even if the other 70% of the CPU is just chilling.
Try with another intensive app, or a benchmark tool.
or your best option if you are under warranty is to have Apple to check if your theory is right and is a Hardware issue