The main computer that I’ve been using more and more recently is a Samsung Series 9 Ultrabook. This laptop/ultrabook is rather nice combination of power and size.
Samsung Series 9
My setup involves having the laptop off to the side on a cooling mat, while it is hooked up to an external keyboard and monitor. (This allows for a more ergonomic set up as I can use a Kinesis Advantage keyboard as well as various trackballs/mice.)
However even with the cooling mat, I’ve noticed that the laptop seems to run rather warm.
I used Speedfan to measure the fluctuating temperature of the laptop under various loads. The laptop seems to idle around 55°C under normal usage (running chrome and a few text editors). However, if using something more intensive, such as a full-screen Skype video call, the laptop runs anywhere from 60 to 70°C. I’ve even seen the laptop get as high as 72°C, at which point the cooling fan in the laptop seems to be running as fast as possible and sounds like a little jet engine.
Not only is this annoying to listen to, but I’m concerned about the lifetime of the fan. I’ve had to replace fans in laptops before and they are not cheap. So in this light I decided I would disassemble the laptop and attempt to re-seat the heatsink with better thermal compound.
The laptop is surprisingly easy to disassemble. A few simple screws on the bottom to remove and the bottom cover pops off. From here most of the important things are accessible (excluding things like the keyboard and such).
Removed back cover
There is a single heatsink in the laptop that serves both the CPU and GPU. This heatsink also has a copper heat pipe to transfer heat away from the CPU towards the radiator fins by the fan.
Removing the heatsink is also very straightforward. There are 5 Philips screws to remove and it simply pops right off. I also took the blower fan out and cleaned it out. There was some dust in the radiator fins as well that was easily removed.
Removed the heatsink
CPU & GPU dies
I cleaned off the old thermal compound and insured the surfaces or sparkling clean using 99% isopropyl rubbing alcohol. (If you’re doing any electronic or computer-related work I recommend the 99% alcohol rather than lower concentrations like 50%. The reason is that the 99% concentration ensures there are less impurities in the liquid itself as well as it dries much quicker saving you a bit of time.)
All clean and shiney
I was rather surprised at the thermal compound that Samsung chose to use for the laptop. Normally in laptops they use some form of cheap thermal compound that tends to dry rather quickly and become crusty and flaky. Or even worse, sometimes cheap laptop manufacturers won’t even use thermal compound and will instead use thermal pads that sit between the CPU die and the heatsink. Samsung had chosen to use a somewhat decent thermal compound that was still slightly liquid in nature.
As a replacement thermal compound I decided to use the Arctic MX-4 as I had some leftover from when I built a desktop computer.
Arctic Thermal Compound
After reassembling the laptop and putting the bottom back on I tested it and measure the temperature with Speedfan again.
All done & heatsink back on
I wasn’t expecting a very large difference considering that Samsung had used a seemingly decent quality thermal compound before, but I was pleasantly surprised with the results. The laptop now idles around 47°C, and under higher load with a full-screen Skype video call the temperature peaks at about 66°C. (That’s a 8°C difference while idle and a 4-6°C difference under load)
It’s rather amazing that you can get an approximate 5°C temperature drop just by using a better quality thermal compound. Absolutely nothing else was changed in the laptop, and I did not change any settings in the software/operating system.
Full disclosure: One thing I did not account for in these measurements was the ambient temperature of the room. Obviously having a higher temperature in the room would cause a higher temperature for the CPU.
That said, the measurements before and after were done on the same day in a relatively short period of time, and the temperature was relatively constant throughout the day.
Overall I’m rather pleased with the end result. The cooling fan in the laptop no longer needs to run at full speed all the time while the laptop is under load.