Thermal Paste Round-up: 85 Products Tested

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.

MORE: Best CPU Cooling

MORE: How To Choose A CPU Cooler

MORE: All Cooling Content

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93 comments
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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?
    3
  • 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!
    1
  • 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.
    3
  • DarkSable
    Hang on, I'm sorry.

    Quote:
    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.
    3
  • 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.
    0
  • 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.
    0
  • 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.
    5
  • 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.
    1
  • 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.
    1
  • AndrewJacksonZA
    A great article, thank you! :-)
    0
  • joz
    Interesting, I didn't expect my preferred TIM, Antec Formula 7, to do "poorly" as it did. But that's really only in comparison to the exotics. Compared to the standard TIMs, it is slightly above middle. However, of all the TIMs I've seen or used - the Formula 7 seems to have the best shelf-life. I had a few tubes of various other TIMs around - BeQuiet's included paste for the H7, and old bottle of Zalman (like...9500AT top of the game old), MX-4, and others. Of those, only the Formula 7 hasn't had any sort of separation or drying out issues. The same tube I've had for about 8 years now, and its still just as good as it was when I got it.

    Also, its one of the easiest to apply and get good coverage out of.
    0
  • FormatC
    @JamesSneed:
    This was really not easy to learn. I tried different methods with my chiller (to get at least one stable factor for a comparison in this tests). It is at the end more important to get the thinnest but perfect film without any bubbles and not the biggest possible area/surface. TR is soldered (thx for that) and the IHS is really stable. You need a good compromise between pressure and the amount of used TIM. Mostly is less better ;)

    My best friends are good torque screw drivers ;)

    2
  • mapesdhs
    Strange, I'm not seeing inline images for this article (FF 54.0.1).
    1
  • daglesj
    I would say if folks are concerned with things as trivial as 'paste burn in' then they really need to re-think their lives.
    -1
  • daglesj
    And yeah...images not showing.
    2
  • JamesSneed
    Anonymous said:
    @JamesSneed:
    This was really not easy to learn. I tried different methods with my chiller (to get at least one stable factor for a comparison in this tests). It is at the end more important to get the thinnest but perfect film without any bubbles and not the biggest possible area/surface. TR is soldered (thx for that) and the IHS is really stable. You need a good compromise between pressure and the amount of used TIM. Mostly is less better ;)

    My best friends are good torque screw drivers ;)




    Thanks for that.
    0
  • JamesSneed
    Anonymous said:
    I would say if folks are concerned with things as trivial as 'paste burn in' then they really need to re-think their lives.


    I'm not concerned so to speak but before I set my fan profiles up to keep my computer cool and quite under lower loads I do burn in the CPU with prime 95 for a couple hours just to make sure my temps are what they will be after a burn in. I like to Prime95 a new build to check stability, Overclock it, Prime 95 it, repeat until stable. Then I go in and tweak my fan profiles and other misc features(wait on that just in case I have to do a BIOS rest on OCing). Maybe its just me but how I do it.
    0
  • bit_user
    Thank you! I've been waiting for just such an update!
    0
  • JackNaylorPE
    Anonymous said:
    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!


    One of my disappointments w/ this article is that it leaves out the winner of the last 80 way test like this and that's Shin Etsu which as far as I have seen has the best performance / price ratio out there. My guess is because it's sourced directly from the manufacturer who caters to industrial customers rather than a vendor who buys from an OEM and repackages for the PC industry.

    https://archive.benchmarkreviews.com/index.php?option=com_content&task=view&id=150&Itemid=62&limit=1&limitstart=12

    Shin Etsu equaled AS5s performance in that last 80 way test but AS5 has 3 major disadvantages.

    a) It costs more.
    b) It requires 200 hours of curing time... at 8 hours a day, that's 3-1/2 weeks
    c) The last I will take from A5s home page and concerns potential mishaps.

    Quote:
    Arctic Silver 5 was formulated to conduct heat, not electricity.
    (While much safer than electrically conductive silver and copper greases, Arctic Silver 5 should be kept away from electrical traces, pins, and leads. While it is not electrically conductive, the compound is very slightly capacitive and could potentially cause problems if it bridges two close-proximity electrical paths.)


    Shin Etsu is available from multiple sources for < $4

    It does seem to increase in viscosity over time when exposed to air. Not an issue on CPUs. But when ya doing a GFC card including both sides of thermal pads and both for the back plate and block at VRMs and memory on GFX cards, it can be an issue. Gelid Extreme is good here which is good as that's what is shipped with EK water blocks.
    1
  • AgentLozen
    This was a great article with a lot of information. I've been wondering about the specifics of thermal pastes and many of my questions were answered.

    I wish the author would have discussed what their favorite thermal paste to use was and why. The numbers seem to indicate that the Thermal Grizzly Kyronaut paste typically performed the best and was subjectively ranked high up in the usability category. So in conclusion.......... is this the paste that I should buy for my next PC? Or is there a reason I wouldn't want to? Similarly, the Titan Nano Blue consistently fell to the bottom of the charts. Should I avoid that paste at all costs. The article never really says.

    It may seem like I did a lot of complaining, but I want to reinforce that this article was very helpful. Thank you.
    0