CPU shim
From Wikipedia, the free encyclopedia
A CPU shim (also called CPU spacer) is a shim used between the CPU and the heatsink in a computer. Shims make it easier and less risky to mount a heatsink on the processor because it stabilizes the heatsink, preventing accidental damaging of the fragile CPU packaging. They help distribute weight evenly over the surface.
CPUs are one of the more costly components of a computer, so a CPU shim could be considered a cheap insurance. They can usually be bought for less than USD$10.
CPU shims are usually made of thin and very flat aluminium or copper. Copper has a good heat dissipation capacity but is electrically conductive. CPU shims should be non-conductive to prevent any accidental short circuiting. Aluminium shims are often anodized, which makes them non-conductive and improves their appearance (see case modding). It is also very important that the shim is the proper thickness. If it is too thick then the heatsink will not make contact with the CPU, resulting in poor cooling and possibly overheating.
Most shims are CNC manufactured, often using laser cutting. Cheaper ones may be pressed or stamped which could make them less accurate.
CPU shims are not common at all in OEM computers, but are used by some computer hardware enthusiasts who may use heavier heatsinks because they wish to have a cooler or less noisy system or perhaps to overclock the CPU for better performance. A heavy heatsink puts more pressure on the CPU and motherboard. Shims are very useful for people who often change CPU, heatsink and/or cooling solutions, or use a heatsink that is heavier than the CPU manufacturer's recommended weight.
CPU shims are nowadays obsolete because all modern CPUs since the introduction of the Athlon 64 and Pentium 4 have an Integrated Heat Spreader (IHS) which prevents the CPU core from being accidentally broken.
