What effect does thermal paste have on CPU performance?

Thermal paste plays a crucial role in the performance of a CPU by acting as a medium between the CPU and the heatsink. Its primary function is to fill in microscopic imperfections on the surfaces of the CPU and the heatsink, which helps to create a more efficient thermal interface. By doing so, thermal paste facilitates better heat transfer from the CPU to the heatsink.

When thermal paste is applied correctly, it prevents overheating by allowing the CPU to operate at optimal temperatures. Overheating can lead to thermal throttling, where the CPU reduces its speed to prevent damage, thus impacting overall performance. By ensuring effective cooling, thermal paste helps maintain the CPU at a stable temperature under load, which is essential for sustained performance and reliability during heavy computational tasks.

The other options suggest effects that thermal paste does not have: it does not influence the physical size of the CPU, it does not improve electrical flow, and it does not enhance software execution speed. The crucial aspect of thermal paste is its ability to maintain temperature efficiency, which directly supports the CPU's performance in terms of speed and stability.