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Thermal Paste Round-up: 85 Products Tested

Introduction & Overview

Several years ago, we published a round-up of thermal pastes that started with Thermal Paste Comparison, Part One: Applying Grease And More and concluded with Thermal Paste Comparison, Part Two: 39 Products Get Tested. Since it's so hot outside (at least in our U.S. labs), we're trying to cool so many new CPUs and GPUs, and readers keep asking for it, we decided to combine and update those stories, adding a range of new thermal pastes and pads.

In case you're wondering, toothpaste and denture cream aren't counted in our final tally of 85 contenders. Then again, you might surprised at what dental products can do on a CPU!

Not All Thermal Pastes Are Alike

Because thermal paste is a high-margin product, the market is crowded. While the exact composition of most solutions is a well-kept secret, a Google search makes it pretty easy to get a list of typical ingredients. The upper temperature limit is typically 150°C, though some pastes claim to withstand up to 300°C or more.

The composition of a paste determines its thermal conductivity, its electrical conductivity, its viscosity, and its durability. But what is a paste really made of? Basic compounds consist of zinc oxide and silicone as a binding agent. However, such simple combinations are barely sold anymore. Most vendors start with these ingredients and add other materials, like aluminum. Case in point, the Prolimatech PK1 sports 60-85% aluminum content, 15-25% zinc oxide, and 12-20% silicone oil, as well as an anti-oxidation agent. Some ingredient lists are more mysterious. For instance, the one printed on be quiet!'s DC 1 syringe ambiguously specifies 60% metal oxide, 30% zinc oxide (wait a second; since when is zinc not a metal?), and 10% silicone.

Some pastes, like Arctic Silver 5, even contain silver. Other pastes are based on graphite, like the professional-grade WLPG 10 by Fischer Elektronik. It foregoes the silicone and claims very high thermal conductivity (10.5 W/m·K), but is more difficult to apply and typically electrically conductive. There are also pastes that employ carbon nanoparticles, though they're not suitable for most enthusiasts due to their electrical conductivity and price. The number of copper-based pastes on the market has shrunk, but if you search, you can still find a few.

Silicone is a cheap binder, but it tends to spread. So manufacturers try to constrain this undesirable property or to dispense with silicone altogether in their products. This also applies to so-called "oiling," where the paste virtually dissolves into its base components and the silicone simply oozes away.

There are only a few actual thermal paste manufacturers. Third parties often adapt these bases to create new products with different consistency and color. As a result, many pastes end up almost identical, though they do differ significantly in price.

Pastes Don't Age Gracefully

You may not know this, but thermal paste has a shelf life. Manufacturers usually specify up to three years for unopened packages, but they often forget to tell you when your tube was produced. Thanks to the Tom's Hardware forum members for a reminder of this.

As an example, we tested Innovation Cooling's Diamond 7 Carat and Diamond 24 Carat, which differ only in package size. But the Diamond 7 Carat proved clearly inferior in our benchmarks. Their consistencies were also off. It could have been that such an expensive (bordering on exotic) product sat on the shelf for a long time. An unknowing enthusiast would buy it new, never knowing the compound had degraded.

As a preventative measure, purchase your thermal paste from a larger shop with faster turnover or find a local dealer who can tell you how long your paste of choice was sitting in inventory.

Are The Best Pastes Overrated?

The difference in quality between a celebrated third-party paste and what OEMs use on their builds is smaller than you might think. It's not uncommon to realize a performance improvement by simply bolting your hardware together more carefully. A lot of folks then erroneously attribute this betterment to their new paste.

Also, not so expensive silicone-based solutions despite being easy to apply and affordable, aren't worth the trouble they cause later as they deteriorate.

Liquid metal is suitable for more experienced power users; its application is difficult to master and you may run into trouble with hardware warranty claims, since these "pastes" can never be completely removed without some sort of leftover residue. Given the challenges posed by highly conductive pastes, we'll discuss them separately.

In the end, to achieve above-average performance that is measurably better than what you're already seeing, you need to use the best pastes, and then apply them perfectly.


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  • AndrewJacksonZA
    *heavy breathing*
    I love these kinds of articles and in-depth super tests!! Thank you so much for all your time, effort and hard work, I appreciate it. I'm sure that I'm going to enjoy reading it.

    Um, do you guys still have a single page or "printable" view please?
    Reply
  • Yuka
    Oh, amazing article. I love it a lot.

    Maybe it's because I've used Artic Silver 5 for so many years, but for me it's the best all-rounder compound there is. Plus it's very cheap. I like it more than the MX-2 and MX-4 compound siblings people usually recommends. But I have to say, the "diamond" compounds are indeed better it seems. I had my doubts, but no more with these tests.

    Cheers!
    Reply
  • InvalidError
    Long story short: apart from esoteric TIMs, all pastes are practically as good as any other for typical uses when applied correctly. That really shouldn't surprise anyone as all pastes rely on the same principle of various particle sizes in silicon oil suspension getting crushed together.
    Reply
  • DarkSable
    Hang on, I'm sorry.

    Also, very cheap silicone-based solutions like Arctic MX-2 and MX-4, despite being easy to apply and affordable, aren't worth the trouble they cause later as they deteriorate.

    I work with MX-4 almost exclusively. Yeah, it's not $30 a tube, but it's also not "very cheap," are you kidding me? "Very cheap," is the Elmer's glue you sniffed as a kid, repackaged as thermal paste.

    I use MX4 specifically because it doesn't have a burn in period and because it lasts FOREVER.

    No, it doesn't deteriorate. I've seen reports a decade after the fact showing less than three degrees celsius difference from when it was first applied.

    So. Either you're biased because of ignorance, or both Artic's warranty and every long term test done before this has been lying. Gosh, lemme think which is more likely...

    Now, is something like MX4 the best thermal paste out there? Of course not. But it IS way better than a lot of the market, super easy to apply and maintenance-free, and very reliable. If you're going to be a snob about your thermal pastes, at least be accurate about it.
    Reply
  • zippyzion
    Well, I didn't see that result coming. They are almost all the same. So, why even bother picking? Just get the cheapest stuff from a reputable name. That's a little disappointing that doubling your money gains you a degree or two, at best.
    Reply
  • grimfox
    Within the article you talk about the considerations for GPU backplate for augmented cooling. Do you plan to do a review/article for products involved in that? I would be interested to know which thermal pads or shims or pastes you are using to augment GPU cooling. And to see a comparison of different products. I recently replaced a laptop GPU and redid the pads for that. The installation did involve a learning curve and finding products was not straight forward.
    Reply
  • JamesSneed
    Nice job on this article. Do more of this It helps the enthusiast community.

    Looking at your data Thermal grizzly Kryonaut wins as the best non-metal TIM except in low mounting pressure situations. it doesn't seem to matter as long as you have one of the decent pastes but its obvious there are a few to avoid like the Coolplast20 or Amasan T12 for example.
    Reply
  • FormatC
    @DarkSable:
    I'm using TIM since over 15 years, not only for Home PC's, but also in the industry. The major problem of this MX-4 are the long Burn-In time to get a better performance and the fast dry-out issue. As hotter a CPU or GPU works, as worse this grease performs (and is drying out). I does a lot of long-term runs with different products and especially this older products (not only from Arctic) were showing this typical behavior.

    If you prefer MX-4, why not? Use it. But please accept, that a test of different products over 4 years can show at the end a completely different picture. :)

    I get a lot of hardware (mostly VGA) with MX2- or MX-4 as replacement of the original TIM from other reviewers in rotation. And I have every time to replace this replacement with better (or original) products to get the original performance back. MX-2 on a VGA card is pure pain. Simply try one time another, better products and you will be surprised.

    @JamesSneed
    I have to take, what's in Germany on the market. All pastes were retail and not sponsored samples from the manufacturer. It was my idea to do this under real conditions. But I think it is possible to organize some stuff also from the US or Asian market.
    Reply
  • JamesSneed
    With Ryzen and more so Thredripper I wonder if those will impact application methods due to the multiple dies under the heat spreader? Seems you would want to make sure you have the area the dies are covered with TIM and that area is spread out more with those CPU's.
    Reply
  • AndrewJacksonZA
    A great article, thank you! :-)

    Reply