How To: Optimizing Your Graphics Card's Cooling

Taking Apart And Re-Assembling Your Graphics Card

Disassembly without Dismay

Prior to starting any disassembly, you'll want to monitor the GPU's temperature at idle and under load for at least 30 minutes using a tool like GPU-Z. It is also helpful to write down the ambient (room) temperature for later reference. These baseline values will help you evaluate the results of any subsequent modifications.

While sayings like "organization is half the battle" may sound cliche, there is a certain wisdom in laying out the screws and parts collected as you take the card apart. That'll help you remember which components go where later. To this end, we're using a small box with multiple compartments and covers to safely separate the screws for inner and outer parts of the card. There is good reason for this, since the screws used in a graphics card can differ ever so slightly (yet significantly) in length or diameter, making it difficult to tell them apart visually.

The actual heat sink is almost always attached to the PCB with four screws that extend from the back through the board. If the cooler also contains a built-in heat sink for the voltage converters, there are usually two or three additional screws for that as well. In these cases, it is important to take the cooler off before dealing with the backplate.

In general, even professionals should go step-by-step and capture each stage in a photo when they aren't 100 percent certain about the process. This could prove helpful down the line if the card needs to be returned to its factory state later for a warranty claim. If the cooler is getting replaced as well, it may also be a good idea to safely put all original parts away in clear plastic bags, labeling each bag accordingly.

Once the seals on the screws are broken, you're at the manufacturer's mercy. If your intent was to check whether or not the screw was properly tightened, you should have tried on one that wasn't sealed. If the screw actually isn't as tight as it should be, your options are to fix it or return it to wherever you bought it. Just remember our earlier warning.

The screws that hold the backplate are their own special story. Not all of them are accessible, let alone removable, from the rear. However, there are almost always technical reasons for this. This is neither meant as a measure to harass you nor as a deliberate barrier for enthusiastic tinkerers.

In our exemplary case, XFX doesn't use an inner assembly and cooling frame that could have served as a counter piece for the backplate's screws. Therefore, the nuts are recessed into the backplate (as seen in the picture above). The heads of the screws are thus on the top side of the PCB (as the picture below shows). These screws are often shorter than those for the voltage converters on the back.

Of course, it is only possible to access those once the cooler itself is completely removed. But even here numerous pitfalls await in the form of various cables and plugs. When in doubt, it's better to play it safe and take one additional photo of whatever similar-looking cables are found to be in close proximity to each other. The connectors should always be handled with extreme care because manufacturers never make those cables longer than absolutely necessary, and the connectors are often a very tight fit. During reassembly, it is important to make absolutely sure that no cable is in the path of the fans prior to putting the screws back in.

Most backplates don't have any thermal contact with the circuit board, unfortunately. At maximum, they come with an insulating foil to prevent short-circuits, just in case.

Note #4: Log several stock temperatures with tools like GPU-Z Just to be safe, document each step with a photo Sort the screws and store them safely Keep an eye on cables that connect coolers and LEDs Never apply force if anything seems to be stuck

Lose the Goop! Start with a Proper Cleaning

Various methods are used to apply thermal paste to graphics cards. Often, paste is applied directly to the heat sink by the cooler manufacturer (via screen printing, pad printing, or using soft pads off a transfer film), or a certain portion of liquid paste is applied later during the marriage of the heat sink to the board.

However, almost all manufacturers overdo it with thermal paste, and in the case of our test subject, the result is messy. We were able to scoop up just over one gram of excess for subsequent tests. We will thus be able to test the same installation under identical conditions with both the original paste and an expensive product, and compare the results.

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Apparently, thermal paste was applied in such abundance that even half of the package was filled as well. While this makes no sense as far as temperatures are concerned, at least it isn't dangerous. Simple silicone-based pastes are generally non-conductive, and thus there is no chance of causing a short-circuit.

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Nevertheless, a thorough clean-up is advisable. As a first step, we recommend using a soft cloth to remove all residue that can easily be wiped off without additional (chemical) aid. When cleaning the heat sink, pay attention to the grating, as remnants of the old thermal paste are easily left behind in the various grooves. This is also true for the surface of flattened heat pipes.

It is important to ensure that those surfaces are thoroughly cleaned because mixing different pastes can be extremely counterproductive. Specialized shops sell cleaning kits for this purpose, but even isopropyl alcohol (2-propanol) will do the trick. It's available on Amazon and at various pharmacies, and usually sold for about two or three dollars per sixteen ounces. It is advisable not to use methylated spirits. And totally unsuitable for the task at hand are acetone cleaners, nitro-cellulose thinners, and nail polish remover. While the latter may also be based on 2-propanol, it often contains other unfavorable additives as well.

Be careful when you're cleaning the GPU package. Avoid scraping or scratching. Even forceful rubbing with a soft cloth can damage the fragile hardware if a certain amount of pressure is exceeded. Whatever remnants are unwilling to part freely are better left alone. Only the GPU itself needs to be polished to a high gloss.

Note #5 Old thermal paste must be removed without solvent as much as possibleDon't use any pointed or sharp objects, don't scratch, don't scrapeApply suitable solvents carefully and in moderationDon't use aggressive solvents (nitro-cellulose, acetone)Avoid solvents around the GPU package; don't leave any puddles

Perfect Application of the Correct Thermal Paste

What makes a paste "correct," anyway? The Internet is full of dubious tests, many of which contradict each other. In fact, any benchmark that ignores the change in fan speeds after modification, or doesn't look at the temperatures of other on-board components are more or less useless.

Except for water cooling, which doesn't need a fan, control mechanisms like AMD's PowerTune and Nvidia's GPU Boost ensure that the GPU's thermal behavior significantly affects fan speed, voltage regulation, and of course clock rate. So, even if the measured temperatures appear the same, the card may suddenly be holding a higher boost frequency for a significantly longer time, the fans may rotate slower, or both. Furthermore, a lower GPU temperature, and thus a reduction of fan activity, can result in a higher thermal load on other components.

The minimum burn-in time necessary for a new application of paste to reach its peak performance is another issue that is rarely taken into account. We have thus allowed all our thermal pastes to "burn in" over a total operating time of 24 hours each. Of course, this prolongs our measurement window, but the extra effort is worthwhile.

Since we generally prefer the "blob" method, and like to tighten the four GPU screws crosswise, the choice of an appropriate paste actually is the most important task. To recap, a lentil-sized blob is more than enough, and it is absolutely okay if a little bit of paste leaks at the sides once the screws are tightened. It's better to be generous than to create empty spaces with no paste at all. Once your burn-in period is completed, it might be a good idea to check whether the four screws need to be re-tightened.

In addition to the paste's basic properties, such as high thermal conductivity (low thermal resistance), its consistency also plays an important role. In the hands of a professional, thermal pastes with high viscosity (like diamond pastes) can be a perfect weapon to battle excess heat. However, for less experienced modders, they're often unpredictable and difficult to handle. To achieve the perfect result with a highly viscous paste, you have to preheat the paste, warm up the heat sink to somewhere between 60 and 70°C, apply the right amount of paste to the sink, and then screw it all back together before the product cools down.

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These two images show that the above pictured blob was sufficient, and hardly any of the product got spilled. Furthermore, the image shows a thin and uninterrupted layer of thermal paste across the GPU, which goes to show there's no reason to fumble with a spatula.

Now it's time to talk money. Not everything that is expensive and/or boldly advertised is suitable for the job. When testing under similar conditions, and by taking fan activity into account, the results reveal relatively small differences. This disqualifies many products due to an unfavorable cost-benefit ratio.

For almost three years, we used Gelid GC Extreme exclusively, and that's after reviewing a number of thermal pastes. Even though Thermal Grizzly's Kryonaut replaced GC Extreme as the weapon of choice for graphics card testing, it's unfortunately also significantly more expensive. On the bright side, you don't need very much of the stuff to modify one graphics card.

Kryonaut is a bit thinner and smoother than Gelid's GC Extreme, yet it doesn't tear. Thus, it is a well-suited candidate for very smooth cooler surfaces. We can recommend this thermal paste in good conscience for all kinds of heat sinks, although there are other suitable alternatives as well.

Note #6: Use only non-conductive pastes; avoid pastes with high viscosity Always question potentially misleading marketing statements concerning thermal conductivity Read several product tests and check the review quality Not everything that is really expensive is also really good Apply the "blob" method with a not-too-viscous paste Tighten screws diagonally and crosswise

Assembly and Functionality Check

Approach the reassembly process by reversing your steps, and don't forget to re-attach cables that were unplugged. After a thorough visual inspection (and comparison to those previously-recommended photos), we proceed to our first check of the card's electrical functions without load using a tool like GPU-Z. Start by logging thermal values at idle.

Given a similar ambient as before, the GPU shouldn't exceed our previous measurements. If it does, something went wrong. We would need to go back to square one and start over. If the temperature isn't higher, gradually increase the load, take the relevant readings, and compare them to the card's previous state. If the fan speeds are lower than before, try adjusting the fan curve to the new, lower temperatures so that the rotational speed matches the previous values.

Note #7 Conduct a thorough visual inspection after completing the reassembly Do a functional check without load Any identified mistakes and issues should be fixed Increase the load slowly, and compare the temperatures to the previous readings under load Allow the paste to burn-in over several hours Remember to check and tighten the screws after burn-in!

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