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Try charging on the right and not on the left

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Re: Try charging on the right and not on the left

#31

Post by bierjunge »

nikanj wrote: post #9
xgbi wrote: post #3

This doesn't make sense, and I'm a bit worried: I "cheaped" out and have a "left side only USB-C" MBPro from 2019. Should I understand that having any kind of load on the measly 2 ports I have on my 1600€ computer will lead to abysmal performance? Like, attaching a USB hub to add basic necessity like HDMI or USB A?

Yes. But the computer is very, very, very thin. Which sells more computers than actual performance under load. Benchmarks show the MB having decent performance, as they start cold and don’t have external devices attached either. Thermal throttling only shows up once you’ve already bought

I have the 2019 MBP 16" with i9 inside and it's terrible for any task heavier than browsing the internet or watching cat videos.

Running CMake + gcc on a bigger project? The fans start running like crazy. The performance of the i9 is awesome, at least for the first 1-2 minutes, after that the CPU is throttling you back to the 90's and the fans are spinning even louder.

But this is not even the funniest issue with it. I have the biggest and most performant charger (96W, pretty much the maximum, because the USB-C standard states, you can only push up to 100W through it). You may think, if Apple put that charger in the box, it should be enough to achieve max performance with it AND still be able to charge it. Nope, but maybe it would be at least enough power, so the battery is not discharged. Lol, nope, higher load for a extended time WILL discharge your battery while being connected to the power supply.

I've tested it with two separate MBP with exactly the same spec (i9 + 32GB RAM + Radeon 5500M 8GB) with exactly the same behavior.

Re: Try charging on the right and not on the left

#32

Post by spuz »

wongarsu wrote: post #13
shrx wrote: post #6

Earlier quoted context omitted.

Documented here: https://support.apple.com/en-us/HT207359

> One of the functions of kernel_task is to help manage CPU temperature by making the CPU less available to processes that are using it intensely. In other words, kernel_task responds to conditions that cause your CPU to become too hot If it's about CPU temperature, why does Apple schedule a task instead of just downclocking the CPU, like everyone else? This question predates the release of M1 Macbooks, and everyone…

They almost certainly do adjust CPU frequency as well (although I don't have a 2020 Mac to check this). Lowering the frequency would mean fewer instructions can be processed per second which means you are more likely to see a higher CPU usage for all tasks. What you see is probably the combination of both of these effects.

It's annoying that the process monitor does not provide any way to distinguish high CPU load due to demand and high CPU load due to a low clock frequency but there is software that can display a CPU frequency chart which can give some insight:

https://pietschsoft.com/post/2020/02/15/macos-monitor-cpu-us...

Re: Try charging on the right and not on the left

#33

Post by matthewmacleod »

wongarsu wrote: post #13
shrx wrote: post #6

Earlier quoted context omitted.

Documented here: https://support.apple.com/en-us/HT207359

> One of the functions of kernel_task is to help manage CPU temperature by making the CPU less available to processes that are using it intensely. In other words, kernel_task responds to conditions that cause your CPU to become too hot If it's about CPU temperature, why does Apple schedule a task instead of just downclocking the CPU, like everyone else? This question predates the release of M1 Macbooks, and everyone…

I'm not an expert, but I know are two forms of throttling under MacOS – the CPU frequency limit, and the "scheduling limit". The CPU reduces frequency under thermal stress just like other machines, but there's a minimum frequency that it can be downclocked to. So if that's not enough to meet the thermal envelope, the scheduler will additionally start to limit the amount of CPU time that can be used. I notice this in particular when the GPU is at full whack – such as running multiple external displays at high resolution with 3D graphics.

Re: Try charging on the right and not on the left

#34

Post by matthewmacleod »

gambiting wrote: post #16
danlugo92 wrote: post #14

Earlier quoted context omitted.

Attach the same monitor to both an M1 and an Intel Laptop, you can fry chicken on the latter.

Can you? My i5-10300H equipped laptop drives two external monitors daily and the fans don't even start in normal use. Maybe specify which laptop? The M1 can't even support two monitors plugged in directly, which is a joke for a machine this expensive.

The M1 can't even support two monitors plugged in directly, which is a joke for a machine this expensive.

That is the case for the M1, which is the lower-end of the new processors – a bit disappointing because I'd've otherwise bought one, but a relatively uncommon scenario overall for a lower-end Mac.

It's not the case for the recently-launched chips, which support up to 2x6k external displays (M1 Pro) or 3x6k + 1x4k (M1 Max).

Re: Try charging on the right and not on the left

#35

Post by remram »

causi wrote: post #5
mkl wrote: post #4

Earlier quoted context omitted.

The comment by jksoegaard may explain it: "the purpose of the thread is to force idleness". I guess it uses up all the CPU without actually making the CPU do anything, so other processes can't use the CPU and produce more heat than it can handle.

That's very interesting. I didn't know it was possible for a process to use the CPU without using the CPU, as it were. Rather I thought the CPU usage was more or less a direct measurement.

I would expect that the CPU frequency would throttle down, rather than regularly running halt instructions.

Re: Try charging on the right and not on the left

#36

Post by jgwil2 »

millzlane wrote: post #28
discardable_dan wrote: post #24

Earlier quoted context omitted.

I have a 2019 MBP that runs hot because it's supporting an external monitor. The year before every laptop became a WFH desktop, Apple decided that running an external monitor could be a massive heat issue and nobody would care. It's literally burning out my work laptop, and soon I'll have to ask IT for a new one. Apple doesn't care, though: they already got paid. As I understand it, though, most of the thermal issues…

They finally made the device a little thicker. Apple could have put a better quality heat sync and fan in these models, they chose not too.

*heat sink

Edit: why is this downvoted? This is a legitimately confusing mistake; people may think it has something to do with synchronization.

Re: Try charging on the right and not on the left

#37

Post by gambiting »

matthewmacleod wrote: post #34
gambiting wrote: post #16

Earlier quoted context omitted.

Can you? My i5-10300H equipped laptop drives two external monitors daily and the fans don't even start in normal use. Maybe specify which laptop? The M1 can't even support two monitors plugged in directly, which is a joke for a machine this expensive.

The M1 can't even support two monitors plugged in directly, which is a joke for a machine this expensive. That is the case for the M1, which is the lower-end of the new processors – a bit disappointing because I'd've otherwise bought one, but a relatively uncommon scenario overall for a lower-end Mac. It's not the case for the recently-launched chips, which support up to 2x6k external displays (M1 Pro) or 3x6k + 1x4k…

Yes, correct, sorry maybe I should have specified.

Re: Try charging on the right and not on the left

#38

Post by znpy »

millzlane wrote: post #28
discardable_dan wrote: post #24

Earlier quoted context omitted.

I have a 2019 MBP that runs hot because it's supporting an external monitor. The year before every laptop became a WFH desktop, Apple decided that running an external monitor could be a massive heat issue and nobody would care. It's literally burning out my work laptop, and soon I'll have to ask IT for a new one. Apple doesn't care, though: they already got paid. As I understand it, though, most of the thermal issues…

They finally made the device a little thicker. Apple could have put a better quality heat sync and fan in these models, they chose not too.

As GP pointed out, apple doesn't care, they already got paid.

I'll go further and I'll say I think it's actual dishonesty on their side: they're providing additional thermal headspace to their own cpus, when instead they have constrained Intel for years.

It's still pointless to point this out, apple users are going to buy apple stuff anyway...

Re: Try charging on the right and not on the left

#39

Post by throwawaymanbot »

the 2019 MBP 13" is garbage. All sorts of wacky issues with it.

I did read that they made the chassis for a different chip that was delayed, and thus anyone who owns one of these, ends up with a chassis that struggles to cool a completely different chip than what was planned. (Im not sure this causes all the other issues however)

Re: Try charging on the right and not on the left

#40

Post by [deleted] »

gambiting wrote: post #16
danlugo92 wrote: post #14

Earlier quoted context omitted.

Attach the same monitor to both an M1 and an Intel Laptop, you can fry chicken on the latter.

Can you? My i5-10300H equipped laptop drives two external monitors daily and the fans don't even start in normal use. Maybe specify which laptop? The M1 can't even support two monitors plugged in directly, which is a joke for a machine this expensive.

[deleted]
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