Hard Disk Drive Random Access Memory (Buffer)

The main part of the random access memory, the size of which in hard disk drives reaches 32 Mb, is used for access optimization, while the rest part of it is used for firmware execution. Many users believe that the increase of the size of the random access memory of the hard disk drive 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 disk drives make ambitious statements about the increase of the size of the random access memory in advertising circulars. However, comparison of almost identical hard disk drives differing only in size of the random access memory reveals that the operation acceleration is only some percent since 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.