Thermal Grizzly TG Putty review

Founded around 12 years ago in Germany, Thermal Grizzly has grown to become perhaps the name associated with cooling products for overclocked, high performance PC hardware. Co-partnered by Roman Hartung (aka der8auer), it's never been one to shy away from trying all kinds of things to squeeze a little more from one's gaming rig, and alongside its range of thermal pastes and pads, it's now offering something called thermal putty.

It's literally marketed as TG Putty, rather than having a 'gamer' name, so at least you know exactly what you're getting. It's designed to be used instead of thermal pads in a graphics card and because the electrically non-conductive substance can be spooned or squeezed into place, all the guesswork about what thickness of pad one requires is removed.

At least, that's the theory, because in practice, knowing exactly how much putty to apply is difficult to ascertain. Thermal Grizzly provides some guidance on the product page but the whole process has a significant degree of trial and error to it.

There are three grades of TG Putty to choose from (Basic, Advance, and Pro) but other than some fairly generalised descriptions of their thermal conductivities ('moderate, good, excellent') and putty colour (pink, blue, and silver-grey), you'll left to determine which version is most suitable for your needs on the basis of price.

All variants of TG Putty come in a 30 g (1.06 oz) tub, along with three plastic spatulas and a very brief instruction manual. A tub of TG Putty Basic will set you back $16 / €15 whereas Advance and Pro tubs cost $26 / €25 and $42 / €40. That's a 168% price difference between the Basic and Pro versions, but without any technical information or statistics, there's no way of knowing whether the Pro is 168% better.

Thermal Grizzly suggests that one 30 g tub should be sufficient to cover the VRAM modules and VRM components on most graphics cards, while two tubs are likely to be needed if one is planning to fill in the backplate area of a card. I received three samples of each version so I set about choosing a suitable GPU to test it all with.

I settled on using a Zotac Gaming RTX 4070 Ti Trinity OC, a card that I bought myself when Nvidia launched its RTX 40-series. It's never had any problems with GPU temperature but in heavy, sustained workloads, the VRAM would frequently reach 90 °C. That's within operating limits but I always felt that with better thermal pads, it could be easily reduced.

Applying the putty

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Above: first application of TG Putty

Above: third application of TG Putty

Thermal Grizzly recommends that any areas where the putty is going to be applied should be cleaned thoroughly with conventional isopropanol, so after stripping down the test card and peeling off the original thermal pads, I wiped the VRAM modules and VRM components with thermal paste remover.

Starting with TG Putty Pro, to get an idea of what the 'best' version had to offer, I initially tried to apply it directly to the heatsink base. However, I rapidly learned that my mental impressions of what the putty would be like, before testing, were wildly misplaced—rather than being a thick, semi-viscous compound, TG Putty is quite delicate and greatly prefers sticking to anything other than itself.

Eventually, I abandoned applying the putty to the heatsink and instead used an entire tub to cover the GDDR6X and power delivery chips that would normally be covered by a thermal pad. As you can see, my efforts were not in the least bit professional looking but in theory, it shouldn't matter. The putty doesn't conduct electricity, so it can be liberally applied to any surface—however, it's important to avoid the GPU die itself.

For testing the thermal performance, I ran a 20 minute loop of 3DMark Speed Way, at a resolution of 1080p. This particular test involves a lot of memory read/writes and works the GPU itself quite hard.

Thermal performance

The above chart shows figures for the GPU's main and hotspot temperatures for an important reason, even though the putty is only being used to predominantly help cool the VRAM. GeForce RTX 40-series graphics cards have a bit of a reputation for undergoing thermal paste pump over time. This is where the thermal paste between the GPU die and heatsink gets slowly squeezed out, leaving the die surface with increasingly less and less paste.

I mention this because RTX 40-series cards generally have the heatsinks attached quite firmly, to apply sufficient pressure on the chip. What I noticed with the first application of the putty is that the GPU's temperatures immediately went to their maximum limits, and the GPU's clocks throttled right back to prevent damage.

The second and third application attempts involved packing more putty in place, to the point where I used almost two full tubs, but I couldn't manage to get the main temperature and hotspot down to the same figures as seen using the original thermal pads.

While the VRAM temperatures were considerably lower, all of this proved to be a huge mistake. After completing the three applications of the Pro putty, I cleaned off as much as I could and then applied the Basic putty, using the same amount as my third attempt with the Pro.

The card managed one full run, with temperatures similar to those as above, but on the second application attempt, the test PC froze completely. It never restarted after that and after trying the graphics card in a number of other PCs, I realised that it had failed completely.

As to why this happened, I suspect the hotspot temperatures are the clue—repeatedly going over 100 °C, and hitting 110 °C in the first test runs, was probably too much for the GPU. I'm still trying to resurrect the graphics card but at the time of writing, it's still dead.

Conclusion

The failure of my graphics card left me conflicted on how to judge Thermal Grizzly's putty. The VRAM temperatures were significantly lower using the putty compared to the original thermal pads, so on that basis alone, it's a remarkable product.

However, it's not in the least bit easy to apply, or at the very least, not cleanly and consistently. During the testing, I had a thought to purchase a large plastic syringe and experiment with squeezing out like a slightly runny dough, but the failure of the GPU put paid to investigating that method.

The single test run I achieved with the Basic TG Putty also suggests that, for most users, it's more than good enough to use. However, at the time of writing this review, Thermal Grizzly was out of stock of the Pro, which suggests that overclocking enthusiasts are only interested in using the best materials, which raises a question as to why Thermal Grizzly thought three variants would be of interest.

But by far the biggest issue with using putty is the fact that some, if not many, graphics cards rely on the thickness and resistance to compression of the thermal pads to ensure the heatsink applies enough pressure on the GPU die. The use of small washers on the heatsink's mounting screens might be a suitable substitute, but this all of this just adds to the trial-and-error nature of the putty.

A single tub of TG Putty Basic is roughly the same in price as a 1.5 mm thick, 120 x 100 mm strip of Thermal Grizzly's TG Minus Pad Basic, a replacement thermal pad. My tests suggest that one tub may not be sufficient and ideally, one would buy at least two, just to ensure one has enough putty to complete the job. The same is likely to be true with the thermal pad, of course, but one isn't saving any cash by using the putty.

For most PC gamers, TG Putty isn't worth buying and the score reflects this. There's absolutely nothing wrong with the product itself, though I question whether there is any significant difference between the three variants. However, as I have amply demonstrated, either through sheer bad luck or just sheer stupidity, the risk to one's graphics card is potentially catastrophic.

Only serious, experienced overclockers are going to be truly interested in the putty, and anyone who has messed about with custom watercooling setups, soldering voltage mods, or delidding CPUs will be right at home with TG Putty. For them, it's certainly worth considering, but as the saying goes, audentes fortuna Iuvat.