A Lenovo W540 was overheating, peaking at 99° before the Intel Core i7 4700MQ would automatically throttle down the speed to prevent permanent damage. A nasty side effect of this is reduced performance. A workstation-grade laptop should be able to handle this kind of heat without issue, what was going wrong!? This was obviously something hardware related since the fan would run at 100% while the air coming out of the fan was room temperature and the CPU was ready to boil water. After disassembling the machine I noticed the heat sink compound wasn’t “smooshed” against the CPU like it should be:
Take a closer look at the image above. What is that desiccant ball doing in there, keeping the heatsink from pressing against the CPU correctly??
Close up of the heat culprit:
I’m going to assume this mistakenly fell in during initial assembly and isn’t an intended feature. After removing the ball and securing the heatsink the compound spread much more evenly:
Prime95 was also happy with the results:
4 thoughts on “Overheating Lenovo W540”
thats not by accident I have had two overheat I think its to keep the heaksink from rocking during install
Just wanted to say thank you for your post. I had been having issues with my W540 overheating (mid to high 90’s) and based on your post decided to take a look. While I didn’t have a plastic ball in mine, the thermal paste they used had completely dried and was no longer transferring heat. Cleaned the old paste off and replaced it with some quality paste and my temps under load are no in the high 60’s to low 70’s.
Your image showing the result may be misleading, as it pictures that your CPU is only running at base clock not utilizing the turbo that actually heats up a CPU up to the 90s. There’s quite a difference between 2.4 GHz and 3.4 GHz in case of a notebook CPU, regarding both performance and temperature.
If you had temperatures of high 90s in the same situation though(no turbo used), then you’re obviously right.
Would be interesting to know what your temperatures are with turbo active, though.
It looks like the 4700MQ can throttle not just on temperature, but also power draw http://www.overclock.net/t/1482572/why-my-i7-4700mq-doesnt-reach-its-maximum-speed
Turbo is definitely enabled on the machine, the default multiplier is 22. I definitely see the power usage peg at 47w, which might be why the CPU isn’t getting up to it’s max turbo multiplier! Good catch!