Using a RAM Drive to Enhance Performance of DISKCOPY (107135)

The information in this article applies to:
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q107135


In MS-DOS 6.2 and later, the DISKCOPY command uses your hard disk drive to temporarily store the data copied from the source disk. This enables single- pass disk copies. If you install a RAM drive, you can increase the performance of this operation.


DISKCOPY uses the location defined by the SET TEMP statement to determine where the data from the source disk should be temporarily stored before it is written to the destination disk.

If you install a RAM drive and define it as your temporary (TEMP) directory, you can redirect the data accessed from the source disk into RAM, thus eliminating the time required for the system to perform read and write operations to the hard disk drive.

To do this:

    Set up a RAM drive in your CONFIG.SYS file using the following parameters:

    device=c:\dos\ramdrive.sys 1480 /e

    NOTE: Make sure the RAM drive is large enough to hold all data from the largest floppy disk drive on your system. (The size given here sets up a 1.44-megabyte RAM drive.
    In your AUTOEXEC.BAT file, change the SET TEMP line to point to the RAM drive as follows

    set temp=<x>:\

    where <x> is the drive letter assigned by the system to the new RAM drive.
The performance gain is not significant on high performance systems with fast processors and hard disk drives; however, it does increase the overall speed of this process on older systems.

Modification Type: Major Last Reviewed: 11/21/1999
Keywords: KB107135