Weird temp/cpu behaviour

[r3drover]

I just recently bought a second hand laptop with an i5-8550u chip. I’m seeing some very high core temps but don’t understand why.

It seems fine - idles at 40c or so. But on websites with graphics or other activities (opening apps etc) it can jump to 90+c for a few secs. And when I’m running an old game it will sit at 95-100c when it’s only using 50% of one core. With the fan roaring. Seems stable and it isn’t throttling but surely that can’t be good.

nervously I ran prime95 to see what it did under full load (fully prepared to power it down) but it was fine. Stable at 80c for 30 minutes with full load on all 8 threads.

the chip has a base clock of 1.8ghz with boost to 4ghz. At full load in prime 95 it’s running at 2.7ghz and 15 watts (the TDP). But when I run the old game or do other activities that see temps spike to 95-100, its running at 4ghz and 30+ watts. Weirdly it’s not above 25% load when it happens.

any way I can prevent it spiking to 100c? I don’t need to run at 4ghz. I’m worried about frying it

 

[Jose Jeswin]

The easiest way would be to edit your power plan to prevent processor core boosting...

change maximum processor state to 98-99% in both plugged in and on battery options..
you wont notice any severe loss of performance and can keep your temps in check..

The second method is to undervolt the processor using a utility called Throttlestop..

you should seriously consider repasting your processor with new thermal paste..

 

[r3drover]

The easiest way would be to edit your power plan to prevent processor core boosting...

View attachment 205433

change maximum processor state to 98-99% in both plugged in and on battery options..
you wont notice any severe loss of performance and can keep your temps in check..

The second method is to undervolt the processor using a utility called Throttlestop..

you should seriously consider repasting your processor with new thermal paste..

Hi Jose - sorry for late reply, I only had a chance to test today. I tried adjusting the power settings but as you say this kills the turbo. My processor speed dropped from 4ghz to 1.8. Not great.

I then tried throttlestop and that worked great. Dropped the voltage by 70mv and the turbo by 400mhz and the temps have dropped by 10-15 degrees. Now it peaks at around 85 degrees instead of 100 with negligible impact on performance. Perfect! Thanks for your advice.

 

[dark2099]

So likely needs a good cleaning, if you have an electric air duster will work wonders, a can of compressed air isn't quite as powerful, but will work, if you feel comfortable enough, can open the laptop and re-do the thermal paste too. As for Throttlestop, I have an i3 of the same generation, have it set to a -250mV on the core, and ~-125mV on the Cache, so you can likely do more, and then not play with the boost speeds, and should be able to get it running completely normal and at better temps. Might be able to drop the voltage on the GPU too.

 

[GerKNG]

i'd say repaste the CPU and it the spikes should lower by a lot.

 

[r3drover]

So likely needs a good cleaning, if you have an electric air duster will work wonders, a can of compressed air isn't quite as powerful, but will work, if you feel comfortable enough, can open the laptop and re-do the thermal paste too. As for Throttlestop, I have an i3 of the same generation, have it set to a -250mV on the core, and ~-125mV on the Cache, so you can likely do more, and then not play with the boost speeds, and should be able to get it running completely normal and at better temps. Might be able to drop the voltage on the GPU too.

ok thanks. Will take the back off and give it a clean. I am used to replacing thermal paste on desktops so if necessary I’m up for that.

I was expecting a bit more of an undervolt but set it at -100mv and a few minutes into testing got a bsod. Wasn’t even at load. I’m comfortable leaving it at -70mv - don’t want to worry about it crashing at any time. I’m not noticing any speed difference from reducing the turbo.

 

[Hyderz]

yeah i had a second hand laptop, which i used for browsing even then the fan stirs up.
repasted it... and fan spin gone.
also there could be dust clogging up the vent holes..

 

[Jose Jeswin]

I had a similar experience with my PS3 super slim...sounded like a jet engine when booting up.... Repasted it with Noctua NT-H1....Now it hardly makes a whisper.