Sunday, 2 September 2018

Lenovo ThinkPad Carbon X1 - Thermal Throttling

I had a feeling that something wasn't just quite right with the laptop. Had it from new for about 3 years, but I noticed that the fan was constantly trying to spin up to max and the general 'feel' in Windows was that things weren't quite as responsive as they should be.

I downloaded and fired up Intel Extreme Tuning Utility and noticed that under load, there were regular periods of thermal throttling.

I recorded the 5-minute CPU stress test output below.
You can see when the blue CPU line goes 100% is when the test started and only a few seconds later, the thermal throttling kicks in. CPU Package temperature is already around the ~85'C.

I had heard that there had been issues with the quality of the thermal compound used in production, so I decided I would clean off the old and apply some new.

It was straight forward to do, undo the screws on the bottom of the laptop, undo the fan connector, then undo the 4 spring loaded CPU heat sink screws. The whole heat pipe assembly and fan can now be removed.

Cleaned off the old thermal compound from the CPU die and off the heat pipe plate, and applied a thin layer of Thermal Grizzly Hydronaught. Re-assembled the laptop, making sure to reconnect the fan!

Off to a good start, the laptop powers back on, it was maybe my imagination, but Windows appeared to load quicker.

Starting up Intel Extreme Tuning Utility again, and setting up another 5 minute CPU stress test, the output recorded below.

What can we see? Well, from the moment the test starts, there was no thermal throttling, and it never kicked in once during the test. The temperature also took a lot longer to rise, and never exceeded 80'c, only briefly touching 80'c towards the end of the test.

Overall, I think the re-application of new thermal compound was a success!