Thermal Compound Roundup - September 2011
By Rafael Otto Coelho on September 6, 2011
Following up on our Thermal Compound Roundup - August 2011 review, we are adding five more thermal compounds to our roundup, for a total of 40 different models from Akasa, Antec, Arctic Cooling, Arctic Silver, Biostar, Cooler Master, Coolink, Deepcool, Dow Corning, Enermax, Evercool, Gelid, Glacialstars, Nexus, Noctua, Prolimatech, Scythe, Shi-Etsu, Spire, Rosewill, Thermalright, Thermaltake, TIM Consultants, 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 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 that 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 that we are including in our roundup.
Figures 2 and 3 illustrate the Akasa 450 gray compound.
We also tested the Rosewill RCX-TC060PRO gray thermal compound, shown in Figures 6 and 7. This compound doesn’t come in a syringe like the others; it comes in a nail polish-like tube, and is applied with an included small brush.
Still looking for good (or, at least, peculiar) “alternative” thermal compounds, this time we decided to try chocolate. Figure 9 shows our CPU with a small amount of chocolate over it, while Figure 10 shows it after the test. It is clear that the chocolate melted in use, spreading itself correctly over the CPU.
For a detailed look at the other thermal compounds included in this roundup, please read our “Thermal Compound Roundup - August 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 11.
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 12 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 oC resolution, we adopted a 2 oC error margin, meaning temperature differences below 2 oC 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)
Cooler Master ThermalFusion 400
Evercool Deep Bomb
TIM Consultants Thermal Grease
Dow Corning TC-1996
|Akasa 450||14 °C||50 °C||36 °C|
|Enermax (Dow Corning TC-5121)||14 °C||47 °C||33 °C|
|GlacialStars IceTherm II||14 °C||49 °C||35 °C|
|Rosewill RCX-TC060PRO||14 °C||56 °C||42 °C|
|Titan Royal Grease||14 °C||52 °C||38 °C|
|Chocolate||14 °C||89 °C||75 °C|
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.
This time, the samples of compounds that we tested had performances that ranged from poor to excellent among the compounds we have tested so far.
For example, the Enermax (Dow Corning TC-5121) compound performed wonderfully, while the Rosewill RCX-TC060PRO had a very bad performance. Please notice that we tested this compound twice (removing it, cleaning the CPU and cooler base, applying it again, and then remaking the test) to ensure that this result was not caused by an installation issue. The results were identical in both tests.
Another odd result was about the use of chocolate as a thermal interface. While the other unusual compounds we tried so far (lipstick, toothpaste, and oil) worked reasonably well as a thermal paste, chocolate proved to be a very bad choice. Actually, in our tests, using chocolate as a thermal compound was worse than using no compound at all.