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Thermal Paste Round-up: 85 Products Tested

Special Case: Thermal Pads & Backplate Cooling

Thermal Pads: A Miracle Or An Illusion?

Let's make it clear that pads are not a suitable alternative to thermal paste between a CPU/GPU and heat sink. They should only be used to cool components like VRMs, chokes, or memory modules, which typically are farther away from the cooling surface.

In the picture below, we see the cheap tape often used to cover voltage regulators. It's not made from a homogeneous material, which would have surely been expensive to manufacture, but rather a foamed mass that is compressed in relevant parts thanks to pressure applied by the assembled card.

Unfortunately, air is one of the worst mediums for transporting heat due to its terrible thermal conductivity. Thus, if compact thermal pads of sufficient thickness and quality are available, we highly recommend using them instead of the stock foam.

Thermal pads (or tapes) are readily available for little money in a variety of thicknesses (and colors). The depression marks on the original tape provide some help on how and where to properly position the product of your choice.

In short:

  • The best thermal pad is just good enough
  • Avoid foamed pads if possible
  • Never use thicker pads than necessary
  • Nevertheless, make sure that there is sufficient pressure on the product

Using The Backplate As A Cooler

Nothing improves cooling like an increase in surface area! So now we're going to show you how to convert an existing backplate to a valuable part of the thermal solution.

Let us quickly flash back to the images of the backplate and the foil glued inside. This foil should either be removed completely (as shown in the picture below) or removed partially with something like an X-Acto knife. You'll want to thoroughly clean any spot that'll be in contact with the thermal pads. Remove any adhesive residue and fingerprint oil. The previously-mentioned 2-propanol comes in useful here.

Keep in mind that with very soft or thin backplates, slight pressure could be enough to make the plate touch the PCB. Thus, the non-conductive foil should only be cut and removed where necessary, or additional tape should be used as an insulating layer in relevant areas. Since this tape can also dissipate heat, that's the preferred solution.

In our specific example—the XFX RX 470 4GB—we put two-millimeter-thick thermal pads directly below the GPU package and one very hot memory module. We used a bit of thermal paste to further improve contact with the backplate, since the plate's inner surface isn't very smooth and also bends slightly under tension.

Since the backplate has a number of ventilation holes, we briefly put it back on prior to installation and marked the holes on the thermal tape. This makes it easier to apply the paste in such a way that there is none in those areas, keeping it from spilling out of the holes. This step is especially easy to see on the yellow pad over the VRMs, where the little blobs are positioned exactly between the holes.

These aren't awe-inspiring improvements, but every degree saved is a positive step forward. The memory modules benefit most, as they now remain well below 194°F (90°C). While this primarily helps operational reliability and durability, it also opens up overclocking opportunities that weren't there before.

Again, to summarize:

  • Remove glued-on foils and remove glue residue
  • Ensure a clean application of the thermal pads; optionally use thermal paste where necessary
  • Be aware of holes in the backplate
  • Avoid short-circuits (conduct a visual inspection, insert a sheet of paper for testing)


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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