Cache buffer HDD
The central part of the random access memory, the size of which in hard disk drives reaches 64 MB, is used for access optimization while the rest part of it is used for firmware execution. Many users believe that the increase in the size of the random access memory of the HDD extremely affects the speed of its work. Using this belief of the users and the reduction of prices on random access memory chips, manufacturers of hard drives make ambitious statements about the increase in the size of the random access memory in advertising circulars. However, comparison of almost same storage devices differing only in the size of the random access memory reveals that the operation acceleration is only some percent of the increased size of the random access memory is used basically for improvement of technology of the read-ahead. The efficiency of the latter dramatically falls in case of casual data access. The size of the random access memory of the hard disk drive is rather small in comparison with the computer random access memory, and greater contribution to the performance of the disk drive at operations with a file system is often paid by the program buffer of the operating system.