Thermal Grizzly Kryonaut vs. Paste X (pre-series) in the thermal paste test: Changing of the guard after 10 years?

Today I’m testing two pastes from Thermal Grizzly. The Kryonaut, which has been following us around for almost 10 years and feels like it’s stuck between every second CPU and its cooler in the forums, and a new paste as a “secret” pre-series product, which will be on the market in around three months. I have already tested this paste internally and today, with Roman’s kind permission, I have the exclusive right to present and compare the product. And I can spoil one thing in advance – the two pastes are really quite different. This also increases the excitement.

But let’s stay with the already known product for now. The success of the Kryonaut is probably also due to the fact that, even back then, it was possible to develop a rather liquid paste that still had quite high thermal conductivity. Due to its consistency, it could usually be applied effortlessly and “foolproof” (if we exclude a few batches), which of course also ensured that it always came out on top in the tests (including mine). A rather slippery paste also results in thinner layers and therefore lower thermal resistance in real life.

With precisely this strategy, i.e. as fluid as necessary and as thermally conductive as possible, they have created a real perennial favorite, without which this company would probably not exist in its current form. But you should always look to the future…

This is exactly where the second paste comes into play. It is relatively viscous, but not quite as solid as the Thermalright TF8 and roughly on a par with the Corsair XTM 70. A paste with a higher filling, i.e. a mixture of soft matrix and significantly more heat-conducting particles, improves performance immensely, but also makes handling a little more complicated. However, the new paste – I’ll just call it Paste X– is still quite manageable. The product doesn’t have a name yet, but I just couldn’t resist using the Grizzly Bear prank. Apart from the taste, the color and consistency are similar, but unfortunately the name is already taken. Maybe you can think of something suitable.

An important foreword on “bulk thermal conductivity” and false marketing promises

I am now deliberately prefacing this with two quotes that not only speak to me from the heart, but also absolutely agree with my laboratory measurements. Conventional pastes cannot achieve much more than 4 to 5 W/(m-K) under the usual conditions on a GPU or CPU in terms of layer thickness, temperature and pressure. Because these quotes are honest and unfortunately correspond to reality, I will use this part from now on as a standard quote in all paste tests of all manufacturers and put it in front. You can’t bend physics.

If you are wondering how you can arrive at figures above this limit, you should know that it is perfectly possible to adapt test conditions in such a way that you get close to astronomically high figures. However, testing in a bucket has nothing to do with reality, even if a known measurement method is used. Without knowledge of the exact circumstances, such values are completely misleading and meaningless. You could give many suppliers credit for simply not knowing any better and just copying the OEM’s data sheets, but it doesn’t make misleading consumers any better.

The previous “reference paste” will only be used for comparisons in the curve diagrams until the automatic, database-based chart generation is ready (soon). Then the best pastes will be used fully automatically for comparison in the charts (can be selected and deselected as with the fans at the time). The Alphacool Apex was and is the tool of choice for me for long-term comparisons, because I have been able to check its behavior for over 12 months. This point will be dropped when we switch to the database.

Real long-term simulations (3000 hours in 1000 cycles up to 90°C) are not feasible in terms of effort. That is why I can only make predictions, but I want them to be understood as such. It is virtually impossible to make scientifically sound statements in just a few days. Yes, you can identify a trend and scale it as a forecast based on existing data, but this is not something that allows you to make really reliable statements. Therefore, I am sorry to say that I have to leave out this important point. However, as far as time permits, I will take community feedback into account and add the comments and long-term experience of third parties to the database as a note in due course, if it seems necessary. In both a positive and negative sense. However, this is a subjective value that has no place in a comparative database.

Unboxing

In addition to the paste, the Kryonaut comes with one or two rubber nozzles as applicators, at least in my large family pack. The initiate likes to use glasses cleaning cloths for cleaning, which are much cheaper in comparison to offers from the computer trade. So you can easily get over the fact that nothing is included here. 🙂

The new Paste X does not yet have any packaging, I only have a standard screw-top jar for internal use. The paste is still a small series and was therefore produced at Thermal Grizzly in Germany. But it will also be my pleasure to test the finished mass-produced product later on.

Technical data

Let’s leave the marketing aside and look at the technical data of this paste, which is available in various containers and sizes. We can see that the information on thermal conductivity is missing (red). The green shaded columns contain my measured values, the gray shaded columns contain the completely missing manufacturer’s data.

Further links and basics