Question Why doesn't my laptop shut down when the CPU gets too hot ?

[Clay201]

I have a Dell Latitude E5570 Laptop with an I7-6820HQ processor, 16GB of RAM, an NVMe drive, and an AMD Radeon R7 M370 (2GB) GPU. It runs Windows 10. I bought it second-hand last year and cleaned it thoroughly, inside and out, after I got it home. The laptop gets used infrequently and when it is, it's just for writing, basic web browsing, maybe a bit of Youtube here and there. For anything that requires heavy lifting, I have a desktop.

Whenever I do use the laptop, I find that its bottom gets alarmingly warm, the side vents pump out very hot air, and even the keyboard and wrist-rest get very warm. I've used plenty of laptops in my day and I don't remember any of them getting this hot externally.

I installed a utility called HWInfo so I could check on the internal temperatures. It reports CPU temps between 110 and 125 F when the machine is idle (1-3% CPU utilization).

To test how it performs under load, I opened the Firefox browser, found a 4K, 30fps Youtube video and let it play, resulting in 45-50% CPU utilization. Under these conditions, HWInfo reports CPU temps fluctuating between 175 and 190. When I switched to a 4K, 60fps video, CPU utilization increased to 75% or so and temperatures soon climbed as high as 208. At that point, the numbers turned red, so I closed the browser. Temps dropped back down to 130-145 and utilization dropped as well.

I discovered that the system was using the onboard graphics processor and ignoring the Radeon R7, so I disabled the onboard graphics in the device manager. The system began using the Radeon R7 instead, but it resulted in no change to the internal or the external temps.

In the UEFI (or BIOS, if you prefer) I disabled an option identified as "Intel SpeedStep" but this also failed to change anything.

I'm sure I'll end up removing the CPU heatsink, checking everything out as best I can, cleaning whatever there is to clean, then applying some fresh thermal paste and putting everything back where it belongs. But before I do that, I need to know...

1. Why didn't my computer shut down when the CPU temps reached 208? I've had computers overheat before and they always shut themselves down (or at least rebooted) when they got too hot. Is this feature malfunctioning on my laptop? And if it is, how do I fix it?

2. Why is there so much external heat even when the CPU temps are within normal range? This isn't normal. What's going on?

3. What is a normal temperature range for my CPU? Google says that anything north of about 190 is too high. HWInfo seems to think it can go up to about 200. What's the limit? And where should my numbers be when CPU utilization is at, say, 50%? How about 75%?

 

[Lutfij]

It reports CPU temps between 110 and 125 F when the machine is idle (1-3% CPU utilization).
If the F wasn't placed there by accident, then it's 37.8 Deg C and 51.6 Deg C, respectively. That's fine.

To test how it performs under load, I opened the Firefox browser, found a 4K, 30fps Youtube video and let it play, resulting in 45-50% CPU utilization. Under these conditions, HWInfo reports CPU temps fluctuating between 175 and 190. When I switched to a 4K, 60fps video, CPU utilization increased to 75% or so and temperatures soon climbed as high as 208.
https://www.dell.com/support/manual...36cfd7-e9b0-4602-885c-54d3c4579ba2&lang=en-us
4K on a laptop that ultimately output 1080p on your display is an unrealistic test to subject the laptop under.

208 Deg F is 98.3 Deg C
https://www.intel.com/content/www/u...r-8m-cache-up-to-3-60-ghz/specifications.html
below 100 Deg C as stated in TJunction.

If you're concerned about temps, I'd advise using ThrottleStop and undervotling the CPU vcore, cache, iGPU and then the discrete GPU.

 

[Clay201]

Thanks for the reply.

208 Deg F is 98.3 Deg C
https://www.intel.com/content/www/u...r-8m-cache-up-to-3-60-ghz/specifications.html
below 100 Deg C as stated in TJunction.

Thank you. This solves one mystery. The laptop didn't shut down because it didn't quite reach the upper temp limit. However, I'm still alarmed that it came so close to the limit while the CPU utilization only reached 75%. This certainly sounds to me like the CPU is running hotter than it should. What do you think?

(Presumably, the fix will still be some cleaning and some new thermal paste. I just want to make sure I understand what's going on.)

 

[JayGau]

Thanks for the reply.


Thank you. This solves one mystery. The laptop didn't shut down because it didn't quite reach the upper temp limit. However, I'm still alarmed that it came so close to the limit while the CPU utilization only reached 75%. This certainly sounds to me like the CPU is running hotter than it should. What do you think?

(Presumably, the fix will still be some cleaning and some new thermal paste. I just want to make sure I understand what's going on.)

What's surprising is that the CPU is loaded at 75% while only watching youtube. But it's an old CPU with only 4 cores so it might not take very much to load it. And laptop thermals are also not always great. With this CPU I assume it's an old computer. You could try to open it and blow out the dust from the fans, heatsinks and vents. If there is some piled dirt or dust inside that prevents the heat to get out, the CPU and the latop itself will get hot.

 

[Clay201]

What's surprising is that the CPU is loaded at 75% while only watching youtube. But it's an old CPU with only 4 cores so it might not take very much to load it. And laptop thermals are also not always great. With this CPU I assume it's an old computer. You could try to open it and blow out the dust from the fans, heatsinks and vents. If there is some piled dirt or dust inside that prevents the heat to get out, the CPU and the latop itself will get hot.

As I said in my original post, It's very clean, both inside and out. I suppose there could be dust and gunk hiding underneath the heatsink. I haven't taken that off yet and I don't know how much room there is under there.

But regarding the temperature, I'm a little confused... Are you saying that a CPU temp of 98.3 C is not unusual when it's at 75% utilization?

 

[Misgar]

Are you saying that a CPU temp of 98.3 C is not unusual when it's at 75% utilization?

It depends on several things:

What was the ambient temperature of the room where you were using the laptop? If, for sake of argument, it was a sweltering 104°F (+40°C), I wouldn't be surprised if the CPU peaked at 208°F (+98.3°C) at 75% load. Even at 71°F (+21°C) ambient room temperature, the laptop will still get warm.

Next, consider where the laptop is located. If it's sitting on top of a bed and the air intakes underneath are completely blocked, the cooling fan(s) won't be able to move air through the heatsink vanes.

If the fan bearings are failing or the blades don't spin up to maximum revolutions, cooling will be compromised.

If the laptop contains two fans, but one fan has stopped working, cooling may be inadequate.

CPU-World shows the i7-6820HQ has a nominal TDP rating of 45W. That's a considerable amount of heat to dissipate in a non-gaming laptop.
https://www.cpu-world.com/CPUs/Core_i7/Intel-Core i7-6820HQ Mobile processor.html

It's possible Dell may have tailored the profile of the i7-6820HQ so that it doesn't use all 45W, to increase battery life. As an example of the heat being produced, you wouldn't hold a 40W Tungsten light bulb in your hand very long when illuminated.

Many laptop heatsinks are a compromise because space and weight are at a premium. If a desktop PC has a powerful CPU, you can fit a huge dual tower heatsink or triple fan AIO. As a result, laptops designed for portability might not always have the best cooling possible.

Presumably, the fix will still be some cleaning and some new thermal paste.

I've repasted hundreds of desktop CPUs, but never touched a laptop. I'm wary of possible difficulties if the laptop manufacturer used thermally conductive epoxy resin glue, as opposed to standard Silicone oil-based thermal paste.
https://www.masterbond.com/properties/thermally-conductive-epoxy-adhesives

Removing a laptop heatsink could be tricky when glued down. If the heatsink refuses to budge, don't apply brute force and potentially damage the Silicon die. Check out a few repair videos for your particular laptop before proceeding.

If your laptop doesn't shut down when the CPU is near the boiling point of water, the cooling system is maintaining temperatures within the "thermal design envelope".

I'd leave off repasting the CPU unless the laptop crashes repeatedly under load and accept that a 45W processor will get toasty warm at times.

 

[Clay201]

What was the ambient temperature of the room where you were using the laptop? ...
Next, consider where the laptop is located.

The room is about 72 degrees and the laptop is sitting on a small table next to my desk, so no problems there. Even when I tried using it in bed, I ended up getting a little "lap desk" to set it on. However, there's a large vent on the bottom of the laptop and I do question whether the the almost non-existent feet are holding the computer up high enough to allow for adequate airflow down there. I hoped I was being paranoid on this point and that Dell wouldn't design something so poorly, but maybe they did.

If the fan bearings are failing or the blades don't spin up to maximum revolutions, cooling will be compromised.

If the laptop contains two fans, but one fan has stopped working, cooling may be inadequate.

Sure, but I would certainly classify both of those scenarios as "unusual." That is, the processor is getting hotter than it should, the computer isn't functioning as intended.

For the record, though... there's only one fan in there and, considering the impressive force with which it expels hot air through the side vent, I'd be surprised to learn that it's not functioning at 100%. Still, it's worth checking just to be sure.

[T]he i7-6820HQ has a nominal TDP rating of 45W. That's a considerable amount of heat to dissipate in a non-gaming laptop.

I would be low-grade appalled to learn that Dell designed this machine to work this way, but it's certainly a possibility I've considered. We'll see how it turns out. And anytime I'm shopping for laptops in the future, I'm going to check the TDP rating for the processor. I appreciate you mentioning this.

I'm wary of possible difficulties if the laptop manufacturer used thermally conductive epoxy resin glue, as opposed to standard Silicone oil-based thermal paste.

I didn't even know that was a thing. Thank you very much for the heads up. I will definitely be on the lookout.

Check out a few repair videos for your particular laptop before proceeding.

Most definitely. I do that even if I'm just replacing a hard drive or installing some RAM.

I'd leave off repasting the CPU unless the laptop crashes repeatedly under load and accept that a 45W processor will get toasty warm at times.

If the machine is going to get this warm all the time, I'm going to sell it for parts and get something else. I think I'm willing to chance the re-pasting, but we'll see what the process looks like in the repair videos first.

Thank you for all your help.

 

[Misgar]

anytime I'm shopping for laptops in the future, I'm going to check the TDP rating for the processor.

What you need to bear in mind is that CPUs with lots of cores and high speeds generate more heat.

Older Generation CPUs often generate more heat than newer Generations (per core/per GHz) because the transistors are physically bigger in older CPUs. So an old 4-core CPU running at 2000MHz will usually get hotter than a modern 4-core CPU running at the same speed. Smaller transistors in newer Generations create less heat, but more cores mean more heat.

Your i7-6820HQ (Generation 6) released October 27, 2015 is rated by Intel at 45W.
https://www.cpu-world.com/CPUs/Core_i7/Intel-Core i7-6820HQ Mobile processor.html

As a comparison, my old HP laptop has an i5-7200U (Generation 7) released August 30, 2016 and is rated at only 15W.
https://www.cpu-world.com/CPUs/Core_i5/Intel-Core i5 i5-7200U.html

My i5-7200U is one Generation newer than your i7-6820HQ, but my CPU has only 4-cores 4-threads with a maximum turbo of 3100MHz.

In comparison, your superior i7 has 4-cores 8-threads and a maximum turbo of 3600MHz. It's "better" than my CPU.

As a consequence of having more threads, a higher clock and one Generation older, explains why Intel decided on a 45W power rating for your CPU. It's a "performance" CPU.

If we both ran Handbrake on our old laptops and converted the same video, your laptop would get the job done faster, but dissipate up to 3x the heat (generalization). Handbrake pushes CPUs hard.

My most recent laptop purchased December 2023 contains an i7-13700H 13th Generation CPU. This is now "old" technology, having been superseded by newer Generations.

The i7-13700H has 14-cores 20-threads, a turbo speed of 5000MHz and is rated at 45W, the same as your i7-6820HQ.
https://www.cpu-world.com/CPUs/Core_i7/Intel-Core i7 i7-13700H.html

N.B. The 17-13700HX with 16-cores 24-threads is rated at 55W. The extra threads use more power.
https://www.cpu-world.com/CPUs/Core_i7/Intel-Core i7 i7-13700HX.html

If the machine is going to get this warm all the time, I'm going to sell it for parts and get something else.

I hope the above will convince you that 45W dissipation in a laptop CPU is not unusual. If you want a cooler laptop, buy an i5, or even an i3 processor. What you lose in speed with a "lesser" processor you gain in lower temperatures and potentially longer battery life.

I think I'm willing to chance the re-pasting

If the machine does not crash, I strongly advise against repasting the CPU. By all means check for signs of crumbling thermal paste around the CPU or a loose heatsink, but if it's firmly bolted down try the following:

Open Power Options, Change plan settings, Change advanced power settings, Processor power management, Maximum processor state and reduce the level from 100% to, say, 80%. Tasks may take longer to complete, but the CPU should run cooler.

Alternatively, consider Throttlestop.
https://www.techpowerup.com/download/techpowerup-throttlestop/