Thermal paste charts | igor´sLAB
Paste is not the same as paste!
With so many products on the market, of course, there is also the variety and thus the agony of choice. Their exact composition is in almost every case a well-kept secret, but the margin is not so great and the most important components could usually even be googled. Almost all pastes for CPUs are designed for a temperature limit for continuous operation of approx. 150°C, some even go up to 300°C or higher.
The composition of a paste then also determines the theoretical thermal conductivity, its electrical conductivity, viscosity and long-term durability. But what exactly is in it? The simplest pastes contain for the most part only zinc oxide and silicone as a binder, but are hardly offered as a serious product in this classic form.
The difference in quality between a low-cost third-party paste and what OEM manufacturers use is smaller than you think – and often non-existent. It is also not uncommon to achieve a leap in performance simply by carefully screwing the components together and then, of course, crediting this to the new paste. Very cheap silicone pastes are usually very easy to apply and do not cost the world, but they bring nothing out of work and have been out of date for a long time. Improvements will hardly be achieved, rather a deterioration. This applies to conversions as well as to a newly assembled PC.
Liquid metal is rather something for experienced users and professionals, because the process is difficult to master and you then have the problem with the possible warranty or Warranty, because these «pastes» can never be removed without residue and without a trace, if a hardware defect occurs. The application of these highly conductive pastes and the problem of suitable material surfaces is not without its problems, so we will deal with them separately.
Another point that we must not conceal for a reason is a possible serial fidelity and, above all, the overrun of the storage period of these products.
Manufacturers usually specify up to three years for the period of use of unenlisted packs, but all too often forget the imprint of the actual production date.
Test system and test methods
At the time, we had collected and evaluated many suggestions and wishes of our readers in the forum, which led us in the end to the decision to use all thermal conductive pastes with both water cooling and air cooling using two different assembly variants (contact pressure!) and of course also in use on a graphics card.
Why do we separate all of this into four individual tests? On the one hand, there are the (compact) water coolings, where the temperatures on the heat sink should generally remain well below 60°C, the good air coolers with a very solid fastening and the resulting high contact pressures of the radiator floor on the heat spreader, as well as the «cheap» budget coolers with simple clamping fasteners or Push pins and a little less contact pressure, where you can quickly reach higher temperatures.
Depending on the viscosity and composition, not all pastes are always equally suitable for all applications and are also rarely always equally manageable for newcomers. We also want to include this point in our charts, but as a subjective evaluation, of course.
Let’s first take a look at the systems used for measurements with the CPUs, which for many reasons have not changed over the years. On the one hand, a plausibility test has shown that, on the one hand, the measured distances between the individual pastes do not change or only marginally change on the latest hardware, and on the other hand, the sensors of the older CPUs provide significantly more accurate values than the DTS of the current CPUs. We can therefore measure the exact temperature below the heat spreader, which is extremely important and indispensable for an objective evaluation. Using Tcase instead of Tcore is always the more accurate solution. What always excites us is the long-term durability of all used comnpons, even if we have of course stored both CPUs, as well as the graphics card and the motherboard twice in the archive in case of cases.
the only thing that really needed to be replaced was the power supply after three years.
| Test 1 – Compact water cooler | |
|---|---|
| Cooler used |
Corsair H80i Compact Water Cooling |
| Fan |
Original fan of the H80i, powered by 7 volts unregulated. |
| Cpu |
AMD FX 8350 |
| Motherboard |
Asus 990FX Sabertooth |
| Test 2 – Air cooler with own backplate and solid screwing |
|
|---|---|
| Cooler used |
Be Quiet Shadow Rock |
| Fan |
Original fan of the shadow skirt, speed set to 70% fixed |
| Cpu |
Intel Core2Quad Q6600 Q0 x 2.66 GHz |
| Motherboard |
Gigabyte UP45-UD3LR |
| Review 3 – Intel Boxed Cooler with Push Pins |
|
|---|---|
| Cooler used |
Intel Boxed Cooler |
| Fan |
Original fan, speed set to 80% fixed |
| Cpu |
Intel Core 2 Duo E6850 |
| Motherboard |
Gigabyte UP45-UD3LR |
We have been deliberately using a slightly older card for years (which, thank God, we also own three times) because their cooling solution was very accommodating to our purposes.
With only 4 screws for the cooler, a very easy to fix fan speed and the core temperatures, which are still justifiable in the higher range due to the larger structure width, we do not run the risk of the possible failure of the test object in the event of a bad paste. Risk. However, the chip size and achievable surface temperature are roughly what a today’s mid- and upper-class GPU offers.
| Test 4 – Graphics Card Test |
|
|---|---|
| Cooler used |
Zalman GPU Cooler |
| Fan |
Original fan, speed set to 80% fixed |
| Cpu |
ATI Radeon HD 4850 |
| Lab |
Testystem 1 (see above) |
Since the DTS of the CPUs provide rather hypothetical results for the core temperatures Tcore, we use, as already mentioned, the good old evaluation of Tcase on the thermal diode under the heat spreader.
Since all CPUs used for the test still have soldered heat spreaders, this method is probably the closest thing to the whole thing.
In the case of CPUs, we rely exclusively on the difference value (delta) from room temperature and tcase, as despite countermeasures in the room there were always slight deviations and these could distort the result for Tcase a little bit. In the case of the graphics card, however, we again use the measured value for the GPU diode, as it remains relatively independent of fluctuations in the (air-conditioned) room temperature as long as this is within the range of less than 2 Kelvin deviation from the initial value 22°C
| Measuring conditions | |
|---|---|
| Ambient temperature | Eel 22°C (relatively constant between 21.4 and 22.7 °C) |
| Results CPU tests |
Output in °C as delta-T, cumulative mean (temperature difference between the ambient temperature and the values of the thermal diode under the heat spreader) |
| Results GPU Test |
Output in °C for the GPU diode |
| Measurement passes CPU |
1x 4 hours burn-in, then at least 2 hours break 4x 1 hour measurement, in between 1 hour breakTotal time at least 16 hours per product and cooler |
| Measurement passes GPU | 1x 4 hours burn-in, then at least 2 hours break 2x 1 hour measurement, in between 30 minutes breakTotal time at least 8.  5 hours per product |
Thermal compound buying guide — Newegg Insider
Not All Thermal Paste are the same
Since thermal compounds are a high-margin product, it’s no surprise that the market is so crowded. But it’s vital to note that the products aren’t all alike. The upper temperature limit of a liquid metal thermal paste can reach 150°C, although there are some pastes on the market that claim to be able to withstand temperatures of up to 300°C, and even more.
The composition of a compound determines its thermal and electrical conductivity, its durability, and its viscosity. Pastes are made of a wide range of ingredients including:
- Zinc oxide
- Silicone oil
- Ceramic
- Aluminum
- Copper
- Silver
- Graphite
- Carbon nanoparticles
- And various anti-oxidation agents
PC enthusiasts can opt for a metal, silicon, carbon-based, or ceramic thermal compound, but it’s crucial to choose one with the ideal properties to cater to their specific needs.
For instance, a gamer with a CPU that’s overclocking at breakneck speed needs to have the assurance that all the heat is being efficiently moved away from their computer’s internals, so they might choose a metal paste which has the best conduction properties.
Metal Thermal Compounds
These are the most effective heat conductors, but they are also very electrically conductive. This means that extreme care must be taken when applying the paste on the motherboard’s metal contacts.
Ceramic Thermal Compounds
These don’t contain any metal, which means that they are not conductive. These are significantly cheaper, safer to use, and they provide great results. That is why they are so popular. However, they won’t provide as large a decrease in temperature as the liquid metal thermal paste does.
Silicone Thermal Compounds
These are pre-applied to thermal pads which are then placed between the processor and the heatsink.
Silicone thermal pastes are very easy to use, but they don’t offer the same effectiveness as the other types of compounds.
It’s best to avoid adhesive heat sink paste as it permanently sticks to whatever components it is used on. So, if the need ever arose to replace the cooler, for example, there would be problems in doing so.
Things to Consider When Buying Thermal Paste
Getting the wrong kind of paste will not only increase the PC temperature but it may also worsen its performance. Adequately applying the right thermal gel will keep the CPU/GPU cool without overclocking or overheating.
These are a few factors for computer enthusiasts to consider before purchasing a thermal compound that will work best to improve the temperature, as well as the performance of their PC.
Open Hub Shaft Tip
Round-end Manual Push Plunger
4g Thermal Conductivity Barrel
Thermal Conductivity
The second factor to consider is the thermal conductivity of the paste.
It’s important to choose a paste with the proper thermal conductivity levels to provide high versatility and total reliability to keep your system safe and cool. Each thermal paste comes with its own thermal conductivity rating for how efficient it is at transferring heat from the processor to the heatsink. When the thermal conductivity of a paste is more than the temperature of the components, then it’s reduced even more.
Liquid and non-metallic compounds have different conductivity levels. For the liquid thermal paste, it’s typically 70W/mK (watts per square meter of the surface area), while non-metallic compounds have a conductivity of between 4-10W/mK. As a general rule, the higher the number rating, the better the compound is going to be at heat conduction.
Density and Viscosity
In order to enhance the process of application, it’s important to choose a thermal paste that has the right density. This will allow it to squeeze throughout the CPU easily.
Liquid thermal paste has a significantly lower density than normal thermal paste, but it’s also notoriously hard to apply. When choosing the right paste, care must also be taken to ensure that the paste has the right consistency for applying it directly to the CPU or GPU without risking damage to the components.
The higher the viscosity of the compound, the thicker it will be so that it looks more like an actual paste. This type of paste is typically better for sticking the heat sink compound to the processor. Compounds with lower viscosity are typically more liquid, and these tend to leak onto the motherboard easily when too much of the compound is used.
Conductive or Non-Conductive
Applying a thermal compound to the processor or other parts of the PC requires absolute care because it’s possible to experience harmful short circuits if the paste can conduct electricity. To ensure that there are no short circuits when applying the compound, it’s a good idea to choose a carbon-based compound that is free from any electrical conductivity.
A compound with low conductivity can also be chosen to allow application without shorts, even if the paste touches any of the electrical components.
TDP (Thermal Design Power)
The thermal design power shows the amount of power that a processor is going to use. This can be used as an estimate to determine how hot it is going to get. A processor with higher TDP is likely to use more power and, therefore, generate a lot more heat. This is something else to consider when choosing the best thermal compound to ensure that it can handle the heat generated to keep the components safe, cool, and performing at their best. The TDP is listed on the processor specs.
Cooling Solution
Even with the best thermal compound on the market, it will be next to impossible to bring down the temperature of a system if the cooling solution being used is not a very effective one. PC users need to make sure that the cooling system they’re using is one that can adequately deal with the level of heat that their processor generates.
If not, then the type of thermal compound chosen isn’t going to matter.
How to choose thermal paste. Basic properties of thermal paste.
One of the articles on this site has already talked about how to apply thermal paste to the processor in order to achieve maximum heat dissipation efficiency. But the cooling of the processor depends not only on the correct use of thermal paste, but also on its quality.
In the article, the reader will find information about what properties of thermal paste should be considered when choosing it, as well as the influence of each of these properties on the final result.
Just want to draw attention to the fact that thermal paste is best evaluated by the results obtained in the process of its practical application. There are many independent ratings on the Internet based on testing different brands of thermal pastes.
However, if the brand you are interested in is not in the mentioned ratings, you can assess the degree of its effectiveness by studying the characteristics that are usually indicated on its packaging or on the official website of the manufacturer.
At the same time, the most important among them are:
1. Thermal conductivity
Thermal conductivity — the ability of a substance to transfer thermal energy from its more heated particles to less heated ones. This is perhaps the most important characteristic of thermal paste (the higher it is, the better).
The coefficient of thermal conductivity (eng. — Thermal Conductivity ) is indicated by the symbol λ, measured in W / (m * K) and represents the amount of heat passing through a unit of substance during a unit of time. This indicator can be found on the website of thermal paste manufacturers, and in some cases — on their packaging (see image).
The thermal conductivity of the cheapest thermal paste (KPT-8) is about 0.65 — 0.7 W/(m*K). Among entry-level thermal pastes, a coefficient of 1.5 — 2 W / (m * K) is considered excellent. In most cases, this is completely sufficient for home computer processors, including gaming ones.
For high-performance processors with high TDP, it is advisable to purchase thermal paste of a more «advanced» level.
Its cost is usually an order of magnitude higher, and the thermal conductivity can exceed 5 W / (m * K) and even more.
Well, the coefficient of thermal conductivity of the most effective solutions known today can reach 80 W / (m * K). But ordinary computer stores do not sell such pastes, because they are very expensive, require careful handling, and in ordinary computers they are needed no more than a rocket engine in Zaporozhets.
2. Viscosity (consistency)
Thermal paste should not be too thick or too thin. Viscosity in the range of 160 — 450 Pa * s is considered optimal. This indicator is not often displayed on the websites of thermal paste manufacturers, and even more so on their packaging.
If the viscosity of a specific thermal paste cannot be found, it can be estimated «by touch». The consistency of thermal paste should be slightly thicker than hand cream or toothpaste.
Why does the consistency have to be this way? The thermal conductivity of thermal paste is up to 50 times higher than that of air.
However, it is several tens of times lower than the thermal conductivity of the metal from which the radiator of the cooling system is made. Therefore, thermal paste must be applied in such a way that it fills microcracks on the surface of the processor and heatsink as much as possible, displacing air from there. But its layer should be minimally necessary for this, that is, it should not worsen the fit of the heatsink to the processor and not increase the distance between them.
The thicker the thermal paste, the harder it is to achieve the indicated effect. But if the thermal paste is too liquid, during operation it may leak out under its own weight (when heated, its fluidity further increases).
In practice, an inexpensive thermal paste with optimal viscosity may be more effective than a too thick paste with a higher thermal conductivity.
In addition to thermal conductivity and viscosity, some other properties are also important. However, almost all thermal pastes available for sale today have them within acceptable limits and therefore you can not pay much attention to them.
These are characteristics such as:
• heat resistance — the ability of thermal paste to retain its basic properties regardless of temperature;
• operating temperature range;
• chemically neutral;
• toxicity;
• electrical conductivity.
But if you suddenly decide to use some other substance instead of thermal paste, be sure to consider these characteristics.
For example, some amateur overclockers use mixtures based on soft indium metal instead of conventional thermal paste. The thermal conductivity of indium is high (more than 80 W / (m * K)), but, like all metals, it is also an excellent electrical conductor. If its particle accidentally gets on the motherboard or other computer board, a short circuit will occur with all the ensuing consequences. In addition, indium-based pastes can be highly reactive or even toxic.
How to choose thermal paste. Basic properties of thermal paste.
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Computer maintenance Design and Sale of computers, Consulting Maintenance 1s Service price list Home \ FAQ \ How to choose thermal grease In one of the articles on this site, we already talked about how to apply thermal paste to the processor in order to achieve maximum heat dissipation efficiency. In the article, the reader will find information about what properties of thermal paste should be considered when choosing it, as well as the influence of each of these properties on the final result. I would like to draw your attention to the fact that thermal paste is best evaluated by the results obtained in the process of its practical application. There are many independent ratings on the Internet based on testing different brands of thermal pastes. However, if the brand you are interested in is not in the mentioned ratings, you can evaluate the degree of its effectiveness by studying the characteristics that are usually indicated on its packaging or on the official website of the manufacturer. At the same time, the most important among them are:0064 1. Thermal conductivity Thermal conductivity — the ability of a substance to transfer thermal energy from its more heated particles to less heated ones. The coefficient of thermal conductivity (eng. — Thermal Conductivity ) is indicated by the symbol λ, measured in W / m * K and represents the amount of heat passing through a unit of substance during a unit of time. This indicator can be found on the website of thermal paste manufacturers, and in some cases — on their packaging (see image). The thermal conductivity of the cheapest thermal paste (KPT-8) is about 0.8 W/m*K. Among entry-level thermal pastes, a coefficient of 1.5 — 2 W / m * K is considered excellent. In most cases, this is completely sufficient for home computer processors, including gaming ones. For high-performance processors with high TDP, it is advisable to purchase a thermal paste of a more advanced level. Its cost is usually an order of magnitude higher, and the thermal conductivity can exceed 5 W / m * K and even more. Well, the coefficient of thermal conductivity of the most effective solutions known today can reach 80 W/m*K. 2. Viscosity (consistency)Thermal paste should not be too thick or too thin. Viscosity in the range of 160 — 450 Pa * s is considered optimal. This indicator is not often displayed on the websites of thermal paste manufacturers, and even more so on their packaging. If the viscosity of a specific thermal paste cannot be found, it can be estimated «by touch». The consistency of thermal paste should be slightly thicker than hand cream or toothpaste. Why does the consistency have to be this way? The thermal conductivity of thermal paste is up to 50 times higher than that of air. However, it is several tens of times lower than the thermal conductivity of the metal from which the radiator of the cooling system is made. Therefore, thermal paste must be applied in such a way that it fills microcracks on the surface of the processor and heatsink as much as possible, displacing air from there. The thicker the thermal paste, the harder it is to achieve the indicated effect. But if the thermal paste is too liquid, during operation it may leak out under its own weight (when heated, its fluidity further increases). In practice, an inexpensive thermal paste with optimal viscosity may be more effective than a too thick paste with a higher thermal conductivity. In addition to thermal conductivity and viscosity, several other properties are important. However, almost all thermal pastes available for sale today have them within acceptable limits and therefore you can not pay much attention to them. We are talking about such characteristics as: • heat resistance — the ability of thermal paste to retain its basic properties regardless of temperature; • operating temperature range; • chemically neutral; • toxicity; • electrical conductivity. |
But the cooling of the processor depends not only on the correct use of thermal paste, but also on its quality. 
This is perhaps the most important characteristic of thermal paste (the higher it is, the better). 
But ordinary computer stores do not sell such pastes, because they are very expensive, require careful handling, and in ordinary computers they are needed no more than a rocket engine in Zaporozhets. 
But its layer should be minimally necessary for this, that is, it should not worsen the fit of the heatsink to the processor and not increase the distance between them. 