Its ALIVE ... Fixed thermal shutdown of a Core i5 Laptop with Pentium 4 Heatsink

[DaveLembke]

I get computers given to me on a regular basis from clients who buy new computers and want a free way to get rid of old computers without paying to get rid of them. I go through them and figure out whats wrong with them. They either get disassembled for good parts and toss out the dead guts to recycle or fixed. When fixed I offer them to people as low cost computers for people who need a computer that dont have much money etc. Well in some situations I end up with computers that have problems that I dont have replacement parts for but get creative and modify the system to take universal parts or a part not designed for it.

I was given a Thinkpad that would shut down randomly. The shut down was due to it overheating. Added new thermal compound and that didnt make any difference, its as if the heatpipes arent drawing away enough heat to fins of heatsink. Heatsink fan spins and blows warm air, but doesnt keep up with the Core i5 and is free of dust and spins at almost 4000 rpms. So I decided to make a quick modification to this laptop and add it to my systems that crunch data for BOINC projects in which I put my processing power currently on the Asteroids project. I added thermal compound to flats of the heat pipes at the top of the 2.4Ghz Core i5 M520 CPU and placed a large Pentium 4 heatsink on top of it to passively cool.

When i got this laptop it would climb to above 105C and then shutdown. With adding this heatsink from a Dell tower which use to cool a hot Pentium 4 HT 3.0Ghz, its able to passively cool the Core i5. I have a few boxes with parts and heatsinks I hold onto usually to swap out with one that fails, but in this case to add to a laptop to cool it to safe temperatures.

The spikes in the graph in the pictures are from me showing my 12 yr old daughter how fast a CPU gets hot without proper cooling of a heatsink, temperature plunges upon placing the heatsink back to its surface to draw heat away. So this laptop will be used to crunch data for Asteroids project of BOINC now. 

I suppose I could even use it as a desktop computer with a external display to VGA or HDMI port and USB keyboard and mouse too if I didnt want to use it for crunching data. But this isnt going out the door to anyone modded in a frankenstein manner like this..    Although would be cool for a computer gathering to get attention of the guy running a laptop with a desktop heatsink. 


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[Salmon Trout]

I have been playing around with cooling my i7 4790 system that I bought ready built as a "business computer". The CPU uses the stock Intel cooler, and it doesn't like CPU loads much over 50%. It will idle at around 45 C. Even with the Gigabyte smart fan application set aggressively (100% fan at all times), if I run Prime95 the temperature gets up to 95-100 pretty *censored* quick. I discovered that with the Balanced power scheme you can use Powercfg to set the max CPU frequency so i have written various scripts (batch, VBscript, Autoit) to sample CPU temp in a loop, and if it goes over a trigger value, enforce a lower power state until the temp drops back down. I can run full load apps and have get it cycling between 70 and 75 with an average of 72, which is OK for that CPU. There is a free app called TThrottle which does the same thing, with temp graphs etc.

[DaveLembke]

Cool ... Thanks for sharing that. http://efmer.com/b/

Also, surprised that a ready build business class system would suffer from thermal issues like that for your i7. I thought all systems bought ready built from leading brands are engineered to run full tilt at 100% CPU use for hours without melt down.

Years ago I had a HP Business Class DC5000 SFF Pentium 4 HT 2.8Ghz that would sound like a jet getting ready for lift off with the air ram squirrel cage heatsink HP decided to use for them with variable fan speed.  At full CPU use it was noisy and pumping out lots of heat at the CPU vent but the CPU would max out at 60C

I am actually surprised that with the Core i5 laptop that a client gave me when they bought a newer i7 that the Core i5 didnt thermal throttle and keep itself within safe operating temps and not shut down, but I guess maybe with the failed heatpipe the system might not be able to underclock itself fast enough to recover from the runaway temperature, to which it use to shut down before adding the massive pentium 4 heatsink to it to passively cool.

I am running Linux Mint 17.3 on the laptop and with i7z I can watch the clock of the CPU.

For keeping an eye on temps I have been using PSensor https://wpitchoune.net/psensor/

Its too bad they dont have a TThrottle ported for Linux as for it looks like the perfect band aid for a system that likes to run hot and needs to be throttled to run cooler vs roasting to death. I will try it out though on a Windows 7 system. I have a AMD FX-8350 4Ghz that runs HOT at 72C full tilt and case fan and CPU fan running fast and noisy to pump air through it fast. I should probably invest in a liquid cooler for the FX-8350 as for it pumps out serious heat, but since I havent seen it go over 80C its ok for now, but in the meantime TThrottle could be used to get it running the the 60C range maybe vs being a hot toaster box.