13

I have a new desktop computer with Intel i7-12700 32GB RAM.

I am doing build code stuff, I use the sensors command to check CPU temperature, and I found most of the cores are @ 100C.

Is that normal?

Will CPU hardware itself control the frequency to fit the temperature?

update

I checked dmesg and found many logs as below:

mce: CPUxx: Package temperature above threshold, cpu clock throttled

It looks like the CPU control itself not higher than 100C.

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  • 1
    Irrespective of answers, it is worth noting that Intel CPUs are kind of notorious for running hot, especially in pre-built desktop systems (because most OEMs build under assumptions of typical desktop usage, which rarely needs to actually hit peak CPU utilization). Jan 10, 2023 at 14:42
  • 6
    Did you by any chance build it yourself? The most likely reason — that can even happen to experienced builders sometimes :-) — would be to forget to peel off the protecting plastic from the CPU cooler. Even if you didn't build it but bought it assembled, that would be the very first thing to check (unless the fan obviously doesn't run but you're probably already past that). Unfortunately, it requires removing the cooler and applying paste again (so, if under warranty, let the supplier work on it).
    – Gábor
    Jan 10, 2023 at 14:52
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    you didn't mention motherboard make/model; check BIOS and look if there is a manufacturer defined overclock happening; my ASROCK mobo has this; not saying it's the root cause or should be turned off just something to look into and is very easy to toggle to see if it makes things better or something you prefer
    – ron
    Jan 10, 2023 at 15:31
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    Did you check that the CPU is actually that hot? 100°C is really high, it shouldn't really happen with non-overclocked CPUs that have adequate cooling system. But it might be that your sensors are reporting bogus values, so it's a good idea to check the actual hardware. Try briefly touching the back side of the wall on which the motherboard is mounted — is it hot (it may be considerably cooler than 100°C, but you'd still notice hotness)? What about the CPU cooler?
    – Ruslan
    Jan 10, 2023 at 17:46
  • 3
    How has this not been migrated to superuser.com by now?
    – MonkeyZeus
    Jan 11, 2023 at 20:00

12 Answers 12

19

Whether it’s normal for your system depends on a number of factors; however 100°C is on the high end for a desktop system and you should try to address that. Typically, that would involve improving the system’s cooling: the overall airflow in the case itself (assuming your CPU isn’t water-cooled), the CPU cooler and its interface to the CPU, etc.

In any case, your CPU won’t cook itself: it knows its limits, and it will throttle itself (reduce its frequency) if it needs to cool down. If that happens, you’ll see corresponding messages in the kernel logs (sudo dmesg).

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    older x86 CPUs like i believe[1] the first Pentium and older did not have a way to shut off if they got too hot and could destroy themselves if they got too hot. but every x86 CPU after the original Pentium has a way to shut off if they get too hot. [1] i do not remember the exact year/make/model which had the "shut down if too hot" feature. (fun fact before the "too hot shutdown" feature you could in theory destroy the hardware from software). Jan 10, 2023 at 20:00
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    IIRC Pentium 3 would shutdown if too hot, and Pentium 4 and later would thermal throttle (i.e. keep working at a slower rate). Jan 10, 2023 at 20:05
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    While it's absolutely true that the CPU won't cook itself, a high temperature in the chassis will reduce the life of electrolytic capacitors and hard drives, so there is a reason to try to cool it down.
    – forest
    Jan 10, 2023 at 22:09
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    @user253751 I don't think so. I have a small compute cluster that has been running at 24/7 for years (some of them for almost 10 years straight). The only downtime has been due to fan motors or capacitors. Not one of the CPUs has failed.
    – forest
    Jan 11, 2023 at 21:13
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    Running silicon hot will shorten its lifespan, regardless of your personal data point. Case in point, during crypto peaks buying a used GPU was a bit dangerous, as you could end up with a unit that ran 100% for months or years. One of the most prominent effects is electromigration, it is akin water erosion in rivers. Jan 12, 2023 at 14:31
14

Is that normal?

No, that's very high.

Will CPU hardware itself control the frequency to fit the temperature?

Yes, but you don't want that. Going into thermal throttling means you're getting less performance from the CPU than you could, and spending a long time at elevated temperature will shorten the CPU's life. You want to remove the heat, to avoid both of those problems. You should check on your cooling setup, making sure that the heatsink is in good thermal contact with the CPU (with an adequate, but not excessive, amount of thermal interface material), that the heatsink isn't choked with dust, that all fans are operational, and airflow through the case is adequate.

Oh, and check to see whether someone has compromised your system and installed a cryptocurrency miner that's pegging the CPU and/or GPU to 100% and making things so hot.

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    "a cryptocurrency miner that's pegging the CPU" - OP specified that they're seeing 100°C when compiling code, so I don't think this is relevant.
    – marcelm
    Jan 10, 2023 at 17:18
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    @marcelm: It is relevant if there's cpu-bound malware that's already taxing the cpu's cooling capacity before the code compilation even begins. Jan 12, 2023 at 15:49
  • @ErikKnowles most CPUs shouldn't reach that temp regardless of the workload under normal cooling conditions.
    – Dan M.
    Jan 13, 2023 at 12:56
  • @marcelm: It's a useful thing to check for other future readers with the same symptom but different circumstances from the OP of this question. It's definitely relevant in a StackExchange answer to this question, whether or not it's directly relevant to the querent. But yes, agreed that happening during compile does rule out the OP having a crypto miner, and with Dan that this CPU probably shouldn't get that hot even running Prime95. (IIRC, AMD CPUs do turbo themselves right up to their thermal limits, if electrical current supply and max-frequency allow.) Jan 13, 2023 at 16:26
  • @DanM. Good point. Jan 14, 2023 at 20:23
11

Same sensors command should tell that 100°C is the high temperature threshold eg:

Core 0:        +37.0°C  (high = +100.0°C, crit = +100.0°C)

Once it reaches the high threshold, in addition to active cooling (eg: fan), other method(s) available for the CPU will be used and among them lowering the CPU speed: so the CPU will reach 100°C and stay there due to the negative feedback loop.

If you're worried about the temperature, or more probably annoyed by the fan speed at its maximum, some Intel CPUs (at least Haswell ~ 2013, Skylake or later) along quite recent enough kernel (probably >= 5.4) have a setting to artificially add an offset to lower the temperature threshold (high) at which it will start lowering its speed. In practice that will mean the CPU will reach the newly chosen temperature and stay there, and the fan having less heat to evacuate, will spin less noisily. Of course build time will suffer.

I couldn't find the right subsystem symbolic link to reach it, so here is how I find it (location will probably vary on each system):

$ find /sys -name tcc_offset_degree_celsius 2>/dev/null 
/sys/devices/pci0000:00/0000:00:04.0/tcc_offset_degree_celsius

Then as root:

echo 30 > /sys/devices/pci0000:00/0000:00:04.0/tcc_offset_degree_celsius

will trigger CPU slowing effects at 100-30=70°C. You would now see cores reach, and stay at, 70°C instead of 100°C.

sensors will not know about this except displaying the temperature is now 70°C (which is really the case), but I understand the kernel-related tool turbostat has knowledge about TCC and should be the preferred tool to set the temperature (using --TCC) if it supports the feature for the given CPU (probably meaning it knows what subtraction to do).

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  • Personally I'm using this on my laptop because the fan noise is annoying when building.
    – A.B
    Jan 10, 2023 at 7:00
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    This makes me wonder if OP is confusing the high = +100.0°C as the actual temperature, or something similar.
    – pipe
    Jan 10, 2023 at 14:51
  • Thanks for this, had no idea it was a thing and I'm pretty sure had I known about this I wouldn't have fragged a couple of laptops. Jan 11, 2023 at 20:17
8

In the case of your specific CPU is not normal at all. Make sure that your paste is correctly applied to the CPU and that the heatsink is correctly installed. It must touch the plate surface of the CPU. Also check if your pc case has proper airflow. You can also run a htop(sudo install htop) to see if the usage of your CPU and if it correlates with the high temperatures.

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  • It is clear from the question that the user is seeing high temperatures when they are compiling code.
    – Kusalananda
    Jan 10, 2023 at 15:24
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    "In the case of your specific CPU is not normal at all." - That specific CPU has a turbo TDP of 180W. Without a high-end cooler, I think 100°C might very well be normal stressed?
    – marcelm
    Jan 10, 2023 at 17:16
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    @marcelm 100°C just means inadequate cooling. If a CPU has TDP 180W, the cooling system must be used that can diffuse this amount of power. And, since we see such a round number as 100°C (assuming it's correct), this may mean that the CPU is actively keeping this temperature by throttling, which once again tells that such regime is not normal.
    – Ruslan
    Jan 10, 2023 at 17:53
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    @Ruslan I'm just saying 180W sustained is a lot to deal with, for any air cooling solution. I wouldn't be surprised if for those CPUs with the stock cooler, going into thermal throttling after operating at turbo speeds for extended time is normal. This is already the norm on laptops, and with the huge TDPs of Alder Lake possibly also on desktops. Sure, with a better cooling solution you could have the CPU in turbo indefinitely, which is nice. But what the OP is seeing now could still be pretty much normal.
    – marcelm
    Jan 11, 2023 at 11:06
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    @Ruslan: TDP is a design guideline. Modern CPU's can exceed this, and they will throttle as a result. This is intentional - these CPU's have electrical power specifications that are higher. For this CPU, TDP is a 1 second number average, and there's another 10 ms limit. Also, 100°C is the specified Tj at which the CPU should throttle, so that bit too is by design.
    – MSalters
    Jan 12, 2023 at 10:41
5

Contrary to some other answers, this is normal.

According to Intel's Ark page for the 12700K, the Junction Temperature is rated at 100C. The processor has been set to run up to that temperature limit, and it's considered by Intel to be safe.

That said, it's not ideal because it means there probably is some bottleneck somewhere in removing heat from the processor.

Processors generally run at variable speeds and will often attempt to go as fast as possible until they hit either the max speed set in the bios or the max-rated temperature. Once they hit one of those limits, they will stop going faster and potentially may even slow down to keep from over-shooting the temperature limit. Ideally, they should hit max speed before max temp.

And supposedly keeping temps significantly lower can help improve the lifespan of parts (I believe it but I've also never seen rigorous data on this for modern systems)

There are a few things that can be done to stop this:

  • Make sure the case fans are properly installed (including facing the right direction) and that the case has adequate ventilation. Cases without lots of ventilation will get hot easily. Mesh front cases have become very popular over the last several years because of this.
  • Make sure the cooling system is properly installed on the CPU. This can range from making sure the fan(s) were installed correctly to redoing the thermal paste
  • Sometimes, the motherboard doesn't have good default fan settings for the CPU or case. Adjusting the "fan curves" can sometimes make a big difference (I would do this before trying to redo the thermal paste)
  • Upgrade the cooling system on the CPU. Many pre-builts cheap out on the cooling solution.
  • Go into the system bios and reduce clock settings for the CPU. This isn't necessarily ideal if you want every iota of performance, but modern high-processors are often pushed extremely hard by manufacturers to get every bit of speed for reviews, and it turns out that even a tiny reduction in speed can lead to a massive drop in power usage (and, consequently, heat output).

Just to emphasize this: even pre-built systems from major manufacturers can have issues. Gamers Nexus on Youtube occasionally purchases pre-builts from manufacturers anonymously to review their build quality. They've seen case fans installed backward, cables not fully plugged in, etc. They even had an advanced CPU cooler come with two fans on it facing in opposite directions, effectively canceling each other out.

3

It's not quite normal. You probably need to set PL1 and PL2 power values to something reasonable in your firmware (BIOS). Some motherboards ship with ridiculously high defaults which basically mean unlimited.

The CPU you have can draw a lot of power (above 200W IIRC) and it takes a huge cooler to manage that. Most PCs have a more average cooling solution and depend on soft controls to keep temperatures reasonable. That's what PL1 and PL2 settings do. Without proper values, the CPU will hit its critical temperature limit (100°C) and throttle itself. While this causes no immediate damage, it is apparently not good for long term stability. It also wastes a lot of power for a tiny performance improvement.

I don't know how much truth there is to the possible damage at 100°C. There are no widespread reports of early CPU failures that I know of. You can do nothing, find out, and let us know in a few years.

Or you can adjust the power limits. There's a lot of information about this on the web but the short version is: dial down PL1 until your long build jobs give you a lower stable temperature. I like 80°C but pick whatever you want. The amount of power you set will be what your heat sink can handle and your case fans move out of the way, at that temperature.

Then you can set PL2 somewhat higher than PL1, for short peaks. Think starting an application, displaying a web page, etc. How much higher depends on the termal mass of your heat sink, how long you set the tau parameter, how high you set PL1. Again, the goal is to keep temperature reasonable.

To test PL2, let the CPU idle for a short while then start some CPU intensive job and watch temperature and CPU frequency. You should see temperature rise and eventually frequency drop when PL1 kicks in. If the temperature doesn't rise too much before frequency drops, you're good. If it gets too high to your liking, reduce PL2 or tau.

All the above assumes your cooling system is working correctly. If you're hitting 100°C at low power values (e.g. 65W), you likely have a cooling problem.

3

No It's not Ok.

having a high temperature on hardware (CPU/GPU) got noting to do with kernel it self it's about the task intensity of the program. compiling a code is a high cpu intensive task.

my recommendation is to basically get a better cpu cooler or better thermal paste how ever if you already have above mid-range cooling system make sure you screwd cooler tightly to the mother board and applied enough thermal paste. lastly make sure the case it self has good & correct airflow. you can always increase fan speed but it's noisy.

if you already did all of this i highly recommend to under-volt the cpu from bios. you can also under-clock cores by reducing clock speed if you want to extremely reduce temps but you lose performance.

yes your motherboard will reduce cores clock based on cpu thermal throttle settings in bios but remember you loose performance. i recommend to keep hardware temps below 85°C on max performance if you are planning for long term use.

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    It depends on the specific processor but Intel provides information on temperature settings. Max temperature is often in the range 80-100°C but can be as high as 120°C. The page does state that throttling is used to keep the temperature in check. I have had servers running at the max temperature for weeks on end with no ill effects.
    – doneal24
    Jan 10, 2023 at 15:55
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    @doneal : Trust me ! Getting old is an ill effect, :-) Apart from just kidding… I always noticed that whatever the component, the higher the temperature, the quicker the ageing.
    – MC68020
    Jan 10, 2023 at 16:11
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    @MC68020 While I try to replace servers on a 5-year cycle I am running some for 8+ years. Generally lose a power supply or two and possibly a disk run CPU or mother board failures are rare. Aging on a biological system is a completely different matter that I am well acquainted with.
    – doneal24
    Jan 10, 2023 at 16:18
  • regarding undervolting: I would definitely recommend it, but using a software solution like this can be less fiddly than doing it through the BIOS. I have a 10th gen i7 with less than adequate cooling (due to space constraints) and undervolting 70 or 80 mV has taken my peak temperatures from >100° to 80-75°, without affecting the stability of the system. Jan 12, 2023 at 0:22
  • For long running loads (eg compiling) it may also be useful to manually limit the CPU frequency using a tool such as cpupower. A few hundred mhz slower won't have a huge impact on performance but lowers temps substantially You could even set up a keyboard shortcut to instantly throttle for when unexpected loads arise. Jan 12, 2023 at 0:27
2

TL;DR: Same answer as the rest - not normal for your CPU. But now with authoritative sources, yay!

For Intel 12th gen CPUs, this is not normal. The relevant specification (careful - PDF download) found at the Intel's website clearly states (with minor edits for brevity):

The PROCHOT# (processor hot) signal is asserted by the processor when the TCC [Thermal Control Circuit] is active. [...] When any DTS [Digital Thermal Sensor] temperature reaches the TCC activation temperature, the PROCHOT# signal will be asserted.

And then (emphasis mine):

With a properly designed and characterized thermal solution, it is anticipated that PROCHOT# will only be asserted for very short periods of time when running the most power intensive applications. The processor performance impact due to these brief periods of TCC activation is expected to be so minor that it would be immeasurable. However, an under-designed thermal solution that is not able to prevent excessive assertion of PROCHOT# in the anticipated ambient environment may:

  • Cause a noticeable performance loss.
  • Result in prolonged operation at or above the specified maximum junction temperature and affect the long-term reliability of the processor.
  • May be incapable of cooling the processor even when the TCC is active continuously (in extreme situations).

IF all these measures fail, and there is a risk of physical damage to the product, another signal will go off:

[...] the package will automatically shut down when the silicon has reached an elevated temperature that risks physical damage to the product. At this point, the THRMTRIP# signal will go active.

Relevant conditions are not elaborated, but typically you could expect a "hard" shutdown as late as 115-125°C and as early as 105°C (lower limits are coming from my anecdotal experience). At any rate, temperatures above 125°C are generally seen as extreme, and are a part of industry-standard stress tests such as JEDEC HTOL [high temperature operating life] (pdf download!).

It is important to note that for modern CPUs, there is more to it than just temperatures. Intel tries to cool off long before reaching Tjmax (maximum junction temperature), and the throttling behavior is entirely centered around that temperature. In particular, when trying to go over it, a complex network of regulation of clocks, power limits, C-states and so on will be engaged. For Alder Lake desktop CPUs, Tjmax is 100°C, and this is the temperature referred to in the datasheet above.

By contrast, Ryzen 7000 series reaches Tjmax early and dances around it, boosting opportunistically and throttling as needed, relying on your thermal solution to do its job. Here is a promo/explanatory post from an AMD representative elaborating on this behavior. It also makes sense: larger temperature differences mean more efficient cooling. The main reason this approach is not widespread is because it becomes harder to control, with tiny margins for error. AMD is confident in their ability to keep temperatures under control, and time will tell whether they are right to do so. The reason I bring this up is because "high temperatures=bad" approach is currently being hotly contested: it is kind of like taking a corner in a race car, for a reasonable driver, there is no point in slowing down late - benefits are slim, and the price to pay is high. But you could go faster by taking more risks, which is what AMD does, and the question then becomes whether they can reliably handle it or not.

Either way, whether a given behavior is fine for a given product or not can and should be determined from the relevant design documents. And in your case, hitting Tjmax for a prolonged period of time is specifically described in the datasheet as an indication of an under-designed thermal solution.

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    Especially hitting Tjmax with a workload like compiling is a bad sign;, which doesn't even load the SIMD FMA units. With decent cooling, I'd expect only workloads like Prime95 or maybe video encoding (with software encoders like x265 using AVX2) to hit the thermal throttling limits on a CPU like that. Mostly scalar integer code like a compiler should make much less heat at about the same max frequency. Jan 13, 2023 at 16:33
1

No, that's very hot. Plenty of BIOSes offer temperature checks that stop at 100 degrees.

As other answers said, make sure your CPU is properly cooled; heatsink and fan positioned correctly, air can flow through with minimum obstruction from wires, etc.

There's also maintenance; dust will build up. I typically power off, unplug, dissemble and vacuum my computer at least once yearly. Normally, need to replace the thermal paste on the CPU as well.

To determine if your system is thermal throttling, check the CPU multiplier is close to your CPU expected frequency.
(On Windows, I would recommend CPU-Z. A CPU multiplier of 8 is 800MHz, so a 3.4GHz processor should have a multiplier of 34 when being heavily used.)

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    this is a great answer. CPU-Z is a great app as well, and it does point out great points like the cpu paste. ^+1 Jan 12, 2023 at 9:19
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    I was a bit hesitant to mention Windows because it's the Unix StackExchange. '-'
    – Phi
    Jan 12, 2023 at 9:25
  • no problems with the answer from my side, it's well structured and even though it is as you say Unix SE, I don't see any problem at least including it :) Jan 12, 2023 at 9:26
0

If you want to run cooler but quite a bit slower:-

Create a VM with a reduced number of CPU's and do your compiles in the VM.

I was forced to do a similar thing in a VM for a transcoding application which tried to run 16 threads at 100% each. This caused the temperature to rise above 100°C in less than 10 seconds!

Don't kill your new computer.

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    Many applications (blender, rust compiler, gcc + many more) also have various options to limit the number of threads (cpus) without the overhead of a VM. However if you don't have control over the number of threads then this answer is very useful. Jan 12, 2023 at 0:30
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    Just use taskset to assign cores to a process. A VM is horrible overkill and will cause extra heat due to its own overhead.
    – MSalters
    Jan 12, 2023 at 10:45
  • On the other hand, the number of threads is not the problem. If you have a computer with 16 cores, you should be able to use all 16 cores. The problem is that something is wrong with the cooling system.
    – gnasher729
    Jan 12, 2023 at 12:49
  • It doesn't work like that. You buy the best cooler you can afford. You don't expect to pay for a cooler that sounds like a jet engine. Jan 12, 2023 at 15:55
0

Is it normal? That your computer gets this hot, that is not normal. That it slows down the clock speed and does other things to reduce the temperature in this situation, that is normal.

Does your computer get ventilation / access to cool air? Do the fans work properly? Are they effective? Is there anything blocking cold air from getting to the CPU? Does the temperature get measured correctly? (We know that some thermometer believes it is 100C, that doesn't mean your computer actually is that hot).

Take a thermometer and measure the temperature outside and inside your computer. If it's 40C outside, then move the computer to a cooler place.

-3

Its very hot and may damage your hardware

Until 70ºC is hot, but acceptable. 90ºC or more is just critical. Most CPUs won't reach 100ºC, they shutdown automatically before that.

To-do list

  • Check if it varies with CPU percentual usage (e.g. How much temperature it gets when using 0% cpu?), or if its not related to. If that do not varies, may indicate your sensors are bad.
  • Check air stream: if it can flow inside and outside your pc box, and if everything is clean, incluids your cooler.
  • Test it in a cooler enviroment: test in a room with cool air conditionair or cool motherboard directly with a fan or ventilator. If temperature gets lower, that indicates bad thermal paste or cooler, replace them.

EDIT 1

"Hight temperatures does not damage your cpu"

Yes, it does damage, I didnt mean cpu dies imediatelly, but making it constant makes your cpu to die so much faster

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    This temperature being dangerous is no longer true, modern Intel and AMD CPUs reaching high temperatures is up to specifications. They will down throttle to stay at or under 100 C, 95 C etc. reddit.com/r/Amd/comments/jsy8bw/… Jan 10, 2023 at 23:09
  • 2
    my CPU 20 years ago would hard power off when it hit 100C...didnt damage anything, but I haven't seen that on a long time...as mentioned they throttle speed now.
    – rtaft
    Jan 11, 2023 at 14:30
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    Running components hot will reduce their lifetime. Jan 11, 2023 at 23:46
  • There is one threshold at 100C where the CPU slows down. There is another threshold at some higher point where the CPU will be shut down brutally to prevent damage. Don't know exactly where that point is, but you should never ever reach it. Maybe if you use a hair dryer or use your laptop inside a sauna.
    – gnasher729
    Jan 12, 2023 at 12:47

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