A cache (pronounced as CASH) is a place to store something temporarily in a computing environment. When the user visits a web page, the files requested by the browser are stored on your computer storage in the browser’s cache. If you click the option “back” and return to that page, your browser can retrieve most of the files which it needs from the cache and instead of requesting, they all will be sent again. This approach is called as a read cache. And it is much faster for your browser to read data from the browser cache than to have to re-read the files from the web page.
Types of cache
Write-around cache allows the write operations to be written to storage, skipping the cache altogether. This keeps the cache from becoming flooded when large amounts of write Input/Output occur. The disadvantage is that the data is not cached unless it is read from the storage. As such, the initial read operation will be comparatively slow because the data has not yet been cached.
Write-through cache writes the data to both the cache and storage. The advantage of this approach is that newly written data is always cached, therefore allows the data to be read quickly. A drawback is that the write operations are not considered to be complete until the data is written to both the cache and primary storage. This causes the write-through caching to introduce latency to the write operations.
Write-back cache is similar to write-through caching in which all write operations gets directed to the cache. The difference is that once the data is cached, the write operation is considered complete. The data is later copied to storage from the cache. In this method, there is a low latency in both read and write operations. The disadvantage is that depending on the caching mechanism used, the data may be vulnerable to lose until it is committed to storage.
How to increase cache memory:
Cache memory is a part of the CPU complex and therefore either included on the CPU itself or is embedded into a chip on the system board. Therefore, the only way to increase the cache memory is to install a next-generation system board and a corresponding next-generation CPU. Some older system boards had included vacant slots that could be used to increase the cache memory capacity.