What Is Cache on a STick (COASt)?

What do you get? When you take a stick of RAM and plug it into a computer's USB port? A faster computer, of course! COASt was the first form of external L2 Cache ever built and the coolest. Cache on a STick (COASt) was a physical module plugged into a computer's motherboard and connected to the L2 stock. It used a non-blocking architecture, which was different from the one used by a conventional cache. COASt was used primarily with Rambus DRAM and was popular in the late 1990s and early 2000s when the technology was released. The main advantage of a COASt module is that it can be used to 'hide' the latency of accessing a remote; the performance of the remote computer achieved this by copying the frequently accessed data from the remote L2 Cache to a local COASt module, where I could access it. The most commonly accessed data is stored in DRAM, and the least frequently accessed information is stored on the remote L2 Cache, with the COASt module in between. COASt stands for Cache on a STick, pronounced "coast. " It is a fast pipeline-burst static random access memory (SRAM) technology similar to a large single inline memory module (SIMM). The COASt is especially useful for caching often-used data from disk. This note describes the history behind COASt, its use in various architectures, and some performance results. The COASt is typically installed on the computer motherboard's DRAM channel. The DRAM channel is the electrical pathway between the computer's main memory and the DRAM modules; the DRAM channel will vary according to the computer's hardware configuration. The DRAM channel is often depicted as a series of parallel wires. The DRAM channel is where most data transfers occur between the central computer memory and the computer's DRAM modules. The DRAM channel is considered a high-priority communication pathway. Other active hardware devices may share the DRAM channel.