Because there are so many ways to apply thermal paste, it can be a touchy subject for some enthusiasts. Everyone has their own way of putting paste down to get the best results, but I’ve found that the best temperatures come from the simplest and often simplest way of putting paste down: just one dot.
The “grain of rice” method is another name for this. There are some exceptions to this, like when larger CPUs may need more paste to cover the large surface area or hit specific hotspots under the heatspreader, but the general advice is still the same: a little paste goes a long way.
Before I talk about my favorite way to apply, it’s helpful to know some of the problems that can happen with other ways to apply. The “line method” is the name for one of the most common ways to do things. It’s just like it sounds.
Apply a thin line of thermal paste right down the middle of the IHS (Integrated Heat Spreader), and then let the pressure of the CPU cooler spread the paste out as you secure it.
The problem with this method is that the paste doesn’t get spread out evenly. If you put on enough paste to cover the whole CPU, you’ll probably end up with too much paste. This hurts performance because too much paste makes it harder for heat to move around.
If you don’t leave enough space between the edge of the CPU and the end points of your line, the paste could squeeze out of the sides once the cooler is in place. Not only does this make an unnecessary mess, but if you are using an electrically conductive paste, any contact with the PCB could cause a short circuit, which could damage your motherboard and other connected parts.
Don’t forget that the purpose of thermal paste is to fill in the tiny gaps between your CPU and heatsink, not to sit on top of your CPU like grey cake frosting.
It can be hard to get thermal paste to spread out evenly. Some people say (which is incorrect) that you should use a flat, hard surface like a credit card to spread thermal paste across the CPU. Even though the first results look good and it’s much easier to control how much thermal paste is used, this method has a major flaw that can have a big effect on performance: spreading the thermal paste by hand makes small air bubbles. Since air doesn’t move heat nearly as well as thermal paste, temperatures can drop a lot.
Apply Thermal Paste Using the Dot Method
This method is easy to use and gets rid of the problems that come with other methods. If you install your cooler correctly, it will always work well and spread the thermal paste evenly. Before you start to squeeze the plunger, you should make sure that the surface of both your cooler and your CPU is clean. A quick wipe with an isopropyl alcohol-soaked towel that doesn’t shed will do the trick.
Put a little bit of the thermal paste in the middle of the CPU. You just need a small dot that is a few millimeters across. Don’t go too far, or your performance will suffer. No bigger than one or two grains of rice.
Before you put your cooler together, make sure you have all the parts you need. If you put your cooler in place and then realize you forgot a bracket or backplate, you’ll have to clean up and start over. The thermal paste should be the last thing you do before you mount your heatsink.
Make sure your cooler is as straight as possible when you put it on for the first time. If you have to turn it after it’s already in place to line up the holes, the thermal paste won’t spread evenly.
Note that you will need more than one dot of thermal paste for larger processors like Intel’s 12th Gen Alder Lake CPUs or AMD’s Threadripper chips. Since the processor is no longer square, you can’t rely on one application to spread evenly across the surface of the heatspreader. Instead, I would put two small dots on either end of the processor.
As long as the paste covers the whole chip, you’re good to go. This is important for things like chiplet-based Ryzen processors, which have three separate chips that need to be cooled well. If your program leaves a bald spot on your CPU, it could cause your computer to overheat and run slowly.
When you take the cooler off, you can see that this method makes sure that the thermal paste is spread out evenly. There is enough paste to cover the area of the die without leaking out or making a thick layer that stops heat from moving. When it comes to thermal paste, sometimes less is more, and this is definitely the case.