Applying Thermal Paste, Part Two
The "drop" or "blob" method can be used by both newbies and enthusiasts, and it even works with high-viscosity pastes, assuming you are using a quality cooler that applies plenty of mounting pressure.
Don’t apply too little paste for fear of overdoing it. The compound might end up not covering the hot spot, hurting thermal conductivity and leading to an overheated CPU.
Take the type of cooler into account, too. An aftermarket heat sink with a back plate, which is screwed down, can tolerate less paste than AMD's "hook a clip and flip a lever" or Intel's "four push-pin" sinks. When you use pastes with higher viscosity, you want a cooler able to apply more pressure, and it's alright to use more paste. Of course, when we say more, we mean a little, not an extra-generous slathering.
The picture above shows a near-optimum spread; we wound up with a thin layer that completely covers the die. Since it didn’t reach the edges, we know we didn't use too much paste, and that it wasn't applied too thick. If you know how large a pea is, beware of literally using a pea-sized blob. A paste ball about 1/10” to 1/6” in diameter should be enough; don’t use more than that! We're talking about a lentil-sized ball here.
Last But Not Least: Don’t Panic!
CPU manufacturers also believe in a less-is-more philosophy, as evidenced by their boxed coolers. For instance, AMD’s heat sink only touches about two-thirds of the heat spreader. The stencil-printed paste sports a high viscosity. It's almost solid, and it doesn't spread outwards (the sink's mounting pressure is relatively low). But this method obviously gets AMD’s blessing.
Why do I mention this cheap boxed cooler? To allay fears and to encourage a healthy do-it-yourself sprit. Yes, two decades ago I also had my doubts about mounting aftermarket CPU coolers. But I encourage you to try it with an ounce of preparation, a sprinkle of can-do attitude, and a pinch of carefulness. Nothing will go wrong.