Hard Drive Caching with SSDs

The hard drives we use today are very complex beasts. Cramming that much data onto a very small space while insuring that the data will be there when we need it, is not something easy or simple. The pace of data density increase in hard drives has been nothing short of amazing. At the same time, we all want faster and faster performance from our drives. To help improve hard drive performance, manufacturers introduced a small amount of RAM to the drive. It can be used to hold data for a period of time before writing it to disk, allowing the drive to tell the operating system that the data is actually on the disk, improving application performance. It can also be used to pre-fetch data for reading. In either case, a small amount of RAM can make a very large improvement in performance. If you don’t believe me, run some benchmarks with the disk cache turned on and then off and compare the two results.