A CPU shim (also called CPU spacer) is a shim used between the

CPU A central processing unit (CPU), also called a central processor, main processor or just processor, is the electronic circuitry that executes instructions comprising a computer program. The CPU performs basic arithmetic, logic, controlling, and ...

and the heat sink 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. CPU shims are usually made of thin and very flat aluminium or copper. Copper has 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 Laser cutting is a technology that uses a laser to vaporize materials, resulting in a cut edge. While typically used for industrial manufacturing applications, it is now used by schools, small businesses, architecture, and hobbyists. Laser cutt ...

. Cheaper ones may be pressed or stamped which could make them less accurate. They can usually be bought for less than US$10.

Usage

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 largely obsolete because most modern processors designed for home users since the introduction of the

Athlon 64 The Athlon 64 is a ninth-generation, AMD64-architecture microprocessor produced by Advanced Micro Devices (AMD), released on September 23, 2003. It is the third processor to bear the name ''Athlon'', and the immediate successor to the Athlon XP. T ...

and Pentium 4 have an

Integrated Heat Spreader A heat spreader transfers energy as heat from a hotter source to a colder heat sink or heat exchanger. There are two thermodynamic types, passive and active. The most common sort of passive heat spreader is a plate or block of material having ...

(IHS) which prevents the CPU core from being accidentally broken.

Usage

See also