Thermal Compound Roundup - July 2011
By Rafael Otto Coelho on July 12, 2011
Following up on our Thermal Compound Roundup - June 2011 review, we are adding five more thermal compounds to our roundup, for a total of 30 different models from Antec, Arctic Cooling, Arctic Silver, Biostar, Cooler Master, Coolink, Deepcool, Evercool, Gelid, Noctua, Prolimatech, Scythe, Shi-Etsu, Spire, Rosewill, Thermalright, Thermaltake, Titan, Tuniq, Xigmatek, and Zalman. In this review we will determine if certain products are superior to others. We will also try another "alternative" thermal compound to see if it works.
For a better understanding of how the thermal compound (a.k.a. thermal grease or thermal paste) works and how to correctly apply it, please read our How to Correctly Apply Thermal Grease tutorial and our article What is the Best Way to Apply Thermal Grease? The most important concept that you must understand is that it is a mistake to think that the more thermal grease you apply, the better. The thermal compound is a worse heat conductor than copper and aluminum (the metals usually found on cooler bases). So, if you apply more thermal compound than necessary, it will actually lower the cooling performance instead of improving it.
In Figure 1 there are the five new thermal compounds we are adding to our roundup.
Let's get a closer look at the new contenders in the next pages.
We will now examine the five new thermal compounds we are including in our roundup.
Figures 2 and 3 illustrate the Prolimatech PK-1 gray compound.
Figures 4 and 5 show the Tuniq TX-4 thermal compound, which has a gray color as well.
We also tested the Arctic Silver Matrix thermal compound, shown in Figure 6. It is gray, too.
Figure 7 displays the Evercool T-grease 800 thermal compound. Its color is white.
In Figure 8, you can see the Gelid GC-2 gray thermal compound.
Figure 9 portrays our CPU with Colgate Total toothpaste. It was the best smelling thermal compound we tried so far.Thermal Compound Roundup - June 2011 review.
We tested the thermal compounds using the same testbed system that we currently use to test CPU coolers, which is fully described below. Our Core i7-860 (quad-core, 2.8 GHz) CPU, which is a socket LGA1156 processor with a 95 W TDP (Thermal Design Power), was overclocked to 3.3 GHz (150 MHz base clock and 22x multiplier), and we kept the standard core voltage (Vcore). We used a Zalman CNPS9900 MAX CPU cooler. The only different part in each test was the thermal compound itself.
We measured temperature with the CPU under full load. In order to get 100% CPU usage in all threads, we ran Prime 95 25.11 (in this version, the software uses all available threads) with the "In-place Large FFTs" option. For each test, we applyied the same quantity of thermal compound (about the size of a grain of rice) at the center of the CPU, as shown in Figure 9.
After each test, we checked the base of the cooler, making sure the quantity of thermal compound was optimal. The thermal compound must be spread evenly on the metallic part of the CPU, without exceeding it, creating a thin layer. The "fingerprint" shown in Figure 10 illustrates that the compound was properly applied.
Room temperature measurements were taken with a digital thermometer. The core temperature was read with the SpeedFan program (available from the CPU thermal sensors), using an arithmetic average of the core temperature readings. During the tests, the left panel of the case was open.
We also tested the system with no thermal compound on the CPU.
Operating System Configuration
Since both room temperature and core temperature readings have 1 °C resolution, we adopted a 2 °C error margin, meaning temperature differences below 2 °C are considered irrelevant.
The table below presents the results of our measurements.
|Thermal Compound||Room Temp.||Core Temp.||Difference|
|No Thermal Compound||26 °C||88 °C||62 °C|
|Zalman ZM-STG2||24 °C||59 °C||35 °C|
|Prolimatech Thermal Compound||24 °C||56 °C||32 °C|
|Cooler Master Thermal Compound Kit||23 °C||58 °C||35 °C|
|Evercool EC420-TU15||22 °C||57 °C||35 °C|
|Spire Bluefrost||22 °C||58 °C||36 °C|
|Gelid GC Extreme||26 °C||61 °C||35 °C|
|Coolink Chillaramic||26 °C||61 °C||35 °C|
|Deepcool Z9||26 °C||61 °C||35 °C|
|Noctua NT-H1||26 °C||61 °C||35 °C|
|Thermalright The Chill Factor||26 °C||63 °C||37 °C|
|Antec Thermal Grease||24 °C||58 °C||34 °C|
|Arctic Silver 5||24 °C||57 °C||33 °C|
|Arctic Silver Céramique||24 °C||57 °C||33 °C|
|Biostar Nano Diamond||22 °C||57 °C||35 °C|
|Xigmatek PTI-G3606||22 °C||55 °C||33 °C|
|Antec Formula 7||21 °C||55 °C||34 °C|
|Arctic Cooling MX-4||21 °C||56 °C||35 °C|
|Cooler Master High Performance||22 °C||56 °C||34 °C|
|Thermaltake Thermal Compound||21 °C||54 °C||33 °C|
|Tuniq TX-3||22 °C||54 °C||32 °C|
|Shin-Etsu MicroSi||14 °C||49 °C||35 °C|
|Scythe Thermal Elixer Scyte-1000||14 °C||49 °C||35 °C|
|Titan Connoisseur Platinum Grease||14 °C||49 °C||35 °C|
|Evercool Cruise Missile STC-03||14 °C||49 °C||35 °C|
|Rosewill RCX-TC001||14 °C||53 °C||39 °C|
|Pink Lipstick||14 °C||54 °C||40 °C|
Arctic Silver Matrix
Evercool T-grease 800
Toothpaste (12 h after)
In the following graph, at full load you can see how many degrees Celsius hotter the CPU core is than the air outside the case. The lower this difference, the better is the performance of the thermal compound. The red bars refer to the compounds included in the last batch.
As we concluded previously, there is little difference on temperature performance when comparing good thermal compounds. There are a few exceptions, such as the Gelid GC-2 and the Arctic Silver Matrix, which showed poor performance in this test.
Another interesting finding is that the toothpaste achieved a relatively good performance, being on par with the lipstick we tested last month. However, as we expected, the cooling performance of the toothpaste deteriorates quickly, probably while it loses water by evaporation.