A Socket 478 fan is a component that is placed on a processor or central processing unit (CPU) that is fitted on Socket 478. Also known as Socket N, Socket 478 is a device that semiconductor manufacturer Intel® Corporation debuted in 2000 as a CPU socket for connecting computer chips — mainly from its Intel® Pentium® 4 brand — to motherboards for data transfer within personal computers. The Socket 478 fan is so named because it is designed like a fan; it is actually better known as a heatsink since it technically functions as part of a larger unit. Another more accurate term is "cooler," though it is used far less often than "heatsink."
The socket itself is designed in such a way as to permit the installation of a fan. Socket 478 uses a form factor known as flip-chip pin grid array (FCPGA). This involves the CPU’s die — which is where it houses its processing unit, or core — being flipped around to expose its back. This area is the hottest part of the processor. Thus, when the Socket 478 fan is placed on it, the heat is drawn away from the CPU. This consequently cools down the computer chip, and actually prevents overheating and subsequent malfunction of the computer system.
Socket 478 fans are usually made of black plastic, often have a copper core, and are typically fitted on a block of aluminum. The entire unit has a three-pin connector for users to attach it to the motherboard. Though Intel® created Socket 478, the Socket 478 fans now are made by a variety of computer manufacturers worldwide. It also is important to note that Intel® has replaced Socket 478 with its new LGA 775 socket, also called Socket T.
Specifications of the Socket 478 fan or heatsink vary depending on the manufacturer. Some differences in models include fan size and speed. One manufacturer might produce a 2.36-inch (60-millimeter) fan that spins at 4,800 revolutions per minute (rpm), while another might offer a larger and faster fan at 2.75 inches (70 mm) with an rpm of 5,000. Additional differences include peak noise levels, which are measured in decibels adjusted (dbA), and the rate of air flow, which is measured in cubic feet per minute (CFM). Design differences in the various models can also affect how easy or difficult they are to install.