Thermal Paste Comparison, Part One: Applying Grease And More
If you find yourself fighting a stubbornly-low overclock, there‘s a chance that your thermal solution isn‘t working as effectively as it should. We‘re testing a number of thermal pastes that might help. But first, let‘s go over the basics of CPU cooling.
I’ve been working on this time-consuming thermal compound test for more than half a year, digging my way through the pastes supplied by Caseking (an online shop in Germany) and the ones we already had on-hand in the lab. Not only does a story like this take a lot of time (it involves nearly 40 products, after all), but it clearly requires a consistent test methodology to make sure the conclusions we draw are sound.
Because we have so many products, we‘re splitting the story into two parts. The first one delves into the theory and real-world use of thermal compounds, while the second presents all of our benchmark results and the corresponding test setups.
In part one, we‘ll cover the thermal properties of CPUs, surface types, background information about various thermal compounds and the methods for applying them, as well as two basic cooler types (liquid and air), along with the issues arising from different mounting pressures. A thermal paste working just fine with one cooler may be a bad fit for another. Therefore, we have to test our thermal pastes on AMD and Intel CPUs with a water cooler, a premium air cooler with high mounting pressure, as well as a more pedestrian push-pin setup, which stands in for the boxed heat sinks you get bundled with most processors.
In addition to CPUs, I also test each paste’s suitability for GPU cooling and assess its viscosity and its ease of use. But let’s start with the basics. What is this primordial goo all about?
The Heat Spreader
When you cut a CPU in half, you notice that the chip (die) itself is much smaller than the CPU package, and thus the die touches only part of the heat spreader. The spreader’s job is to distribute the CPU die’s heat across a larger area, which allows it to pass to the CPU cooler‘s heat sink.