Skip to main content

Properly using Thermal Paste to keep your MacBook Cool

I hear a lot of people talking about how their MacBook is too hot.   They look at on-line forums and see that their MacBook is running at 83 C and get very concerned.  They learn from the forums that they need to re-apply the thermal paste to keep their computer cool, but virtually all the forums participants are amateur idiots that offer ridiculous procedures that are likely to damage your computer.

This article is the right way to address this problem.  

First, let's talk about why your computer is running so hot.

Computer CPUs get hot.  They're designed to get hot, consuming many watts in a very small surface area.  Ever touch a 25 watt light bulb that's been on for 5 minutes?  It will be painfully hot.  Take that 25 watts and put it in a much smaller package (think halogen), and it will be MUCH hotter.  That's a CPU - a 25 watt device in a very small package.

CPU manufacturers put temperature probes inside a CPU not so that you can look at the temperature, but so that the computer can regulate its own heat.  No heat sink is going to prevent that CPU from getting hot.  Instead, a heat sink is designed to take that heat and spread it across a larger surface.  Now if that heat sink was huge, you'd be done.  But a laptop is small, so a fan is then used to blow  room temperature air over the heat sink.

Your laptop has fan circuitry that is designed to regulate its temperature.  The fan's cooling ability is based on the ambient air temperature and airflow.  If the computer is feeling hot, it will spin up the fans to exhaust heat.  The amount of cooling is based on airflow and the temperature of the air going into the machine.

So, what about thermal paste?

Thermal paste is simply some heat conducting goop that helps the heat to move from the CPU to the heat sink.  Applying thermal paste is as simple as scribbling with crayons.  And it will last far longer than the life of any machine.  And therefore, "poorly applied thermal paste" or "worn out thermal paste" simply doesn't happen.

All that said, computers can get too hot, particularly when they get old.  Why?  It is almost always due to dust clogging up the airways of your computer, preventing the fans from blowing air over the heat sink.  When a modern computer gets too hot, it will automatically power off.  If you have that kind of behavior, the right response with your computer is to see if you need to de-dust the air passages. Another possibility is that the fan has failed.

So, in conclusion, leave the thermal paste ALONE.  Ignore the forums, as they are filled with idiots and shills that market stupidly overpriced thermal paste.  Let your Mac regulate its own temperature.  If the fan is spinning too hard, it is because you have a runaway process, or because your computer is full of dust.

Popular posts from this blog

Fixing a SodaStream Jet, part 1: Disassembly Guide

I've had my SodaStream Jet for years, and once in a while something has gone wrong. Disassembly is the first step to repair.  Start with this article to see how to disassemble the SodaStream, and then once you have that down, scroll through my other articles to see how I repaired specfic SodaStream problems. SodaStream Jet Disassembly Guide Tools Required Flat head screwdriver Phillips head screwdriver 1. Remove the Carbonator.  Duh. 2. Remove the black panel lever The front big black tilt lever needs to be removed first. Removing this panel is tricky, but it isn't impossible. Looking up at the bottom of the black panel, there are two tabs, one on the left and one on the right. These tabs fully secure the panel in place. The trick is to use a flat-head screwdriver under the plastic to gently lever the tabs out of the way.  Note in the pictures how I approach these tabs with my screwdriver.  I usually release the left side first, and then I release ...

Fixing a SodaStream Jet, Repair #2 - Broken Fill Button

My Soda Stream Jet's fill button broke, which means I can not longer carbonate water by pressing the pushbutton. This caused all sorts of grief in my household. Here is how I managed to repair my Jet to give it another 10 years of life (hopefully). First, a look at the button The fill button on the top of the SodaStream is actually a simple lever. Pressing down on the button moves a pin that does the actual work of pressing open the Carbonator's valve. Unfortunately, the axis point is fairly thin and can see a lot of stress. That's where my Soda Stream button cracked. [ I think the usage tip here is "don't over-press the button like a gorilla, it doesn't do anything but put high stress on the button."] Cracked levering point of the button The Pesky Lever Retaining Pin The Fix It was pretty easy for me to replace the button: Take off the back of the Soda Stream and remove the carbonator. Push out the the button lever's steel retaining pin. This takes qu...

Macintosh: Upgrading an eMac

It's been a long time since I wrote this article, but the fact remains: The good old eMac can still be useful if you take the simple steps to keep it as good as it can be.  All can run Tiger, and most can run Leopard - great operating systems for their day with a bit of useful life.  This article describes the procedure I used to upgrade my old eMac, including: Replacing the internal hard disk with a large capacity drive. Increasing the memory for performance Upgrading the operating system Here I'm upgrading a 700 MHz eMac, but the procedure and tasks for upgrading other eMac models should be almost identical. Upgrading versus Replacing My sister's eMac is of the 700 mhz variety, with 256 MB of memory. The machine seemed to be getting "slower", and the original 40 GB disk was becoming jammed packed with photos and iTunes, and within a few months she'd be out of disk space. There were two options to address the problems: upgrade the eMac, or go o...

Installing a CarPlay radio in a Honda CRV

I ended up buying a 2013 Honda CRV and decided to replace the stock radio/CD player with an upgraded unit.  This was far easier and cheaper than I imagined, but the hardest part was selecting a unit to buy  This article covers how I made my choice.   The basic form factor for my CRV head unit Selecting a Unit The Car I have a 2013 CR/V, which is the same series of all of the CR/Vs from model year 2012 through 2016. Therefore it was important to find a radio unit that fits this model. The CRV has steering wheel radio controls, and I wanted to use them.  This uses a technology called CAN-Bus, which is kind of like USB for cars.  Therefore, a CAN-Bus capability would be able to leverage all these steering wheel features.  In addition, the CRV has a backup camera that would be nice to tie into. And of course I wanted to leverage the existing speakers and USB port. Form Factor I wanted a unit that had a big display, and I wanted a unit that was easy to purchas...

Using a Garmin eTrex with a Macintosh or Linux

The Garmin eTrex series consists of decent, full featured handheld GPS units. The cheaper monochrome eTrex models have a basic RS-232 serial interface, and the color eTrex models sport USB connectivity. In this article I'll talk about my experience with connecting both USB and serial port versions of the eTrex series to my Mac and to my Linux-based PC. I personally use the Garmin Vista HCx GPS now, but the other Garmins in the eTrex series, including the inexpensive but well specified Garmin eTrex Venture should work the same way. Dealing with the eTrex Series with USB Most of the eTrex units with a color screen have a USB port on the back. Happily, this USB port uses a common USB connector, so it is easy to physically connect a USB eTrex to a Mac or a PC running Linux. The USB Port on an eTrex I have found two pieces of software perfect for use with a USB eTrex, without the need for special drivers: GPSBabel+ and Google Earth . The Mac version of the freeware program ...

Old Apple gear that keeps on ticking

I've been dealing with Apple computer gear for a long time, as have my friends and family. Here is a list of the old gear that me and/or my friends have in active service.   Note that this gear is in real service, and isn't treated as museum pieces or as part of a retro-computing hobby. 2008: Apple Airport Express, draft-N, first generation 2009: Apple MacBook, late 2009 (utility use only) 2010: Apple iPod nano, 6th generation 2013: Apple Airport Extreme AC 2015: Apple TV HD (4th generation) The big winner here is the Airport Express, which is modern enough to do its job, and it just keeps on going.  The device that my friend runs has been in operation for more than 125000 hours.  It received its most recent firmware update on 28 August 2018, 10+ years after its initial release. In terms of security: it has no open, unpatched CVE vulnerability reports.  Many generations of other routers have come and go while this one keeps going.

Other Posts

Show more