Thermal pads — forced reality

Content

• Introduction
• Searching for the best
• Testing methodology
• Testing results
• Adding thermal adhesive
• Fixing errors
• Conclusion

Adding thermal adhesive

Koolance T-pads package content includes a small packet of thermal grease, which gives an idea that it is recommended by manufacturer to use thermal paste together with the T-pads.
I decided to check how well the adding of thermal grease on both sides of the pad will effect the temperatures. I took a big syringe of MX-2. Unfortunately, testing using this TIM has led to failure. 0.5 mm thick T-pads from both manufacturers were tested, however, in both cases the result was even worse than with no thermal compound at all. The temperatures in Idle increased by 1-2 ° C, running LinX pretty soon ended in CPU protection triggering and PC shut down.
Thin layer of MX-2 is hard to apply to large surfaces. Let′s just say, that there is an noticeable difference in thickness of the layer and grease appliance to power elements and CPU heatspreader. After several attempts to test T-pads with thermal grease were made, I dismantled CPU cooler to find out that T-pads were stuck hard to the surface of the cooler and CPU heatspreader. When I took off both T-pads they became ruined. Thermal paste has also significantly stuck to the surface and solidified. I suppose, that for adding a thermal paste to both side of the T-pads, it is better to use thermal paste with liquid consistency and stability at high temperatures. Fortunately, I have hound a big syringe of Arctic Alumina lying around at work. This paste has proved itself as a stable workhorse, it does not change its properties within time and is very simple in application. This paste is an insulator, which allows to use it without any fears. All further tests including thermal paste were made using Alumina thermal paste.

Koolance 0.5mm — adding Alumina thermal paste to it almost didn′t effect the overall result. Temperatures in Idle has not changed, I could pass one an a half iterations of Linpack test, which led to the emergency PC shutdown due to CPU overheating.

There was a very quick test of Koolance 1mm T-pads. I only entered BIOS to see the CPU temperature reached 95° a moment later emergency PC shutdown occurred.

Phobya 0.5mm — temperatures did not changed a bit in Idle, however, at full CPU load the temperature reached a critical value of 122°С and never went higher. The test considered to be unsafe and it was stopped manually.

Temperatures in Idle using Phobya 1mm thick T-pads significantly decreased from 52° to 44°С. But the fat pads were unable to withstand the pressure as 0.5mm pads did. I could only pass 2 iteration of stress test when CPU temperature exceeded 126°C which led to BSOD. Well, the situation using Alumina improved slightly.

After removing the cooler, the thermal paste remained in the liquid state, T-pads were not stuck. There is no doubts that the use of Alumina has a positive effect on T-pad performance.