[ The PC Guide | Systems and Components Reference Guide | Motherboard and System Devices | System Cache | Cache Structure and Packaging ]

COASt Modules

Some motherboards use a cache packaging format called COASt, which stands for "Cache On A Stick". This is a silly name for what is in effect a small circuit board similar to a single inline memory module (SIMM) that contains cache SRAM chips on it. It is inserted into a special socket on the motherboard often called a CELP ("card edge low profile"). Some motherboards only use this socket for cache, some have only motherboard cache, and some have both. Usually jumpers are used in this last case to tell the board what is being used, although some boards will autodetect when a COASt module is added. See this procedure for instructions on adding a COASt module to the motherboard.

The CELP socket could have evolved into a standard of sorts for COASt modules, much the way SIMMs and DIMMs are (mostly) standardized in the memory area. However, this has not happened. Despite standard-sounding names like "COASt V1.2" and whatnot, you cannot rely on just any old COASt working in your motherboard. While many manufacturers share COASt module types, many others use proprietary designs. It's important to contact your motherboard vendor or manufacturer to ensure you obtain the correct type for your PC.

Note: The COASt module often contains not just more data store for holding cached entries, but also more tag RAM to allow for more system memory to be cached. See here for more details.

Next: System Resources

Home  -  Search  -  Topics  -  Up