Arctic MX-2 vs. MX-4 Thermal Paste

Suppose you’re looking for a new thermal paste and can’t decide between the Arctic MX-2 and MX-4. In that case, that’s understandable because it’s difficult to pinpoint the significant difference between these two products (aside from the apparent price margin in favor of the MX-2).

I had to buy 20 grams of each Arctic MX-2 and MX-4 thermal pastes and test them separately on my new AMD Ryzen 5 5600X CPU (with a Phanteks TC14PE CPU cooler) to see which performed better across all factors, and my findings are detailed in this article.

But for spoilers, I’d say the MX4 is a newer iteration with minimal differences. However, you’ll agree with me that “minimal” can be significant, especially when it comes down to CPU cooling.

Arctic MX-2 and MX-4 thermal pastes are well-known thermal pastes with distinct properties. MX-2 is non-conductive, but its higher viscosity makes it more difficult to spread. MX-4 has a higher thermal conductivity, is more dependable, is simple to use, and has a low viscosity. Both provide reliable cooling, but the MX-4 performs better. So your choice will be based on whether you prefer the ease of application or cooling performance.

Arctic MX-2 And MX-4 Thermal Paste Compared

We tested the Arctic MX-2 and the MX-4 thermal paste to write this article.
Using these two thermal pastes, the L9i and the Mugan 5, the test evaluated the performance of two coolers.

The results were obtained by measuring the coolers’ performance under different loads and decibel limits.

The results show that the thermal performance of both coolers did not significantly vary between the two thermal pastes.

Additionally, we contacted the manufacturer of the thermal paste, Arctic, to inquire about any other differences between the two pastes. The only difference mentioned was the viscosity of the MX-2, which is supposed to make it easier to apply.

Specs Comparison Table

Specification	Arctic MX-2 Thermal Paste	Arctic MX-4 Thermal Paste
Viscosity	850 P	870 P
Density	3.96 g/cm3	2.5 g/cm3
Volume	0.282 oz.	0.282 oz.
Thermal Conductivity	5.6 W/mK	8.5 W/mK
Material	Non-conductive Carbon	Non-conductive Carbon
Thermal Kit Contents	A syringe with thermal paste and a protective cap	A syringe with thermal paste and a protective cap
Quantity	One tube lasts for 2-3 builds easily.	Not the best option if you prioritize quantity for less money.
Temps performance	Decent, reliable cooling performance	It never went over 76C with all cores at 4.1GHz.

From my experience with these two products, I noticed that the MX-4 is an excellent all-around paste and is perfect for working with GPUs and CPUs. Conversely, MX-2 is thicker and better for direct contact heatpipe style coolers (or rough finish coolers.)

I wouldn’t want to use the MX-2 on a GPU die.

Now let me show you how these two thermal pastes perform in terms of application (manual and spreading), actual temperature regulation performance, and longevity.

Manual application

There’s no massive difference between an MX2 and MX4 regarding applying or cleaning the thermal paste off the HIS or cooler.

MX4 is slightly thicker than MX2, but not much slower, making using or cleaning noticeably more difficult. Although, if I had to side with one of the products based on ease of application, I’d probably support the MX4 since it’s less likely to drip if you overapply.

Thermal paste spread

One is the spreadability of these two thermal pastes, and I had to do a visual experiment on a flat measuring surface to show how they would spread out under a sheet of glass.

I then put down a roughly equal amount of thermal paste to 2 millimeters and waited for one minute. I applied a fair amount of pressure by leaning on the glass panel, and the MX4 appeared to spread out more quickly.

And when it comes to cleaning, it was a breeze for both pastes since I had the electronics cleaner spray.

Thermal temperature testing

It is generally accepted that Arctic MX-4 has a higher thermal conductivity and provides better cooling performance than Arctic MX-2.

But remember that the actual temperature drop will depend on many factors, including the CPU, the cooling system, and the operating conditions. Many factors beyond the thermal paste can influence real-world performance.

Still, the test results did not reflect significant temperature regulation differences enough for us to raise eyebrows.

Both thermal compounds work well when it comes to temperature performance.

Longevity

According to the Arctic brand, the MX 2 thermal paste is better for long-term performance, and this is true.

For gamers who don’t change their paste regularly or ever (for example, using a lightning device), MX-2 is a better choice. But both thermal pastes are expected to last for years under normal conditions.

MX4 achieves better immediate film performance results, so it’s recommended for people who change their paste more frequently, every six months or thereabouts.

In a nutshell

It all boils down to peripheral personal preference, the viscosity you prefer, and the frequency with which you’ll be changing your pace.

But for application, the Arctic MX-2 feels quite stiff if you apply it manually on the CPU surface.

On the other hand, I like the fluidity of the MX-4, which makes it easier to spread around.

The two thermal paste products from the Arctic are metal-free and non-electrically conductive. So whichever product you eventually go with, you don’t have to worry about the possibility of short circuits if some of the paste manages to spill over.

While it is hard to argue temperature differences, I recommend you go for the MX4. It is less thick, easier to clean, has higher cooling properties, and seems a notch higher than its predecessor.

At a dollar more than the MX2, the choice of whether the Arctic MX-4 is worth the extra money is up to you. But you won’t go wrong by going for the one that’s cheaper at the time.

Let me know in the comments what you think about these two products.