Thermal pads — forced reality

Content

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

Testing methodology

Testing the pads or simply checking its main parameter – conductivity — I came with the unusual testing method. It was obvious that the testing should be done using the fullcover waterblock or something like that, for example, motherboard MOSFETS. But just imagine how much work needs to be done: assembling and disassembling the WCS each time you change the T-pad, cut them (pads) to sizes required etc. All this made me think of another way of T-pad testing simple and reliable at the same time. So happened, that I had to work during one of the weekends. So I decided to make a test on my PC at work. It is based on Intel Core2Duo E8400. As it is clear, the CPU was overclocked , core voltage 1.30V in Idle and Load. The CPU was cooled with ASUS Royal Knight AL cooler:

First of all, the surface of the cooler and the heatspreader of the CPU are almost ideal, meaning no additional lapping was required. The base of the cooler is made of nickel plated copper, fins are made of aluminum. There is a 80mm PWM fans in the center of the cooler. The PWM control feature was switched off in BIOS, therefore the fan was rotating at its full speed ~2400RPM.
2×2 cm cuts of each t-pad were made. It′s enough to cover the HIS of the CPU and is about the same size as a box cooler has.
For testing, two system conditions were selected – Idle and Load using LinX (it is a Linpack test with a friendly interface). All energy saving features as well as all CPU protective features were turned-off. The only safety feature built-in inside processor and turning the CPU off when its temperature reaches critical point can not be turned off. This CPU, according RealTemp 3.40 monitoring software, has its critical point at around 125°C. OS Windows 7 Professional 32-bit.
I didn′t make any photos of the testing itself or pad installation etc. In my opinion, is not necessary — everything should be clear. Verbal description and couple of screen-shots of some results should be fairly enough.