MS-DOS: Maximum Usage of FASTOPEN in Expanded Memory (39485)



The information in this article applies to:
    Microsoft MS-DOS operating system 4.0
    Microsoft MS-DOS operating system 4.01
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 5.0a
    Microsoft MS-DOS operating system 6.0
    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 Q39485

SUMMARY

With MS-DOS versions 4.0 and later, FASTOPEN.EXE has been enhanced to allow the use of expanded memory to store the cached information. The amount of expanded memory that FASTOPEN can use is 16K, one expanded memory page.

MORE INFORMATION

MS-DOS Version 4.0

FASTOPEN allows two parameters: (m,n). The m parameter specifies the number of files FASTOPEN can work with, and the n parameter specifies the number of file extents FASTOPEN can work with. FASTOPEN needs approximately 48 bytes for each file and 16 bytes for each file extent specified. Given these values, then you can decide the proper values for (m,n) that fit in one page and provide the optimal performance for the type of work being done.

MS-DOS Versions 5.0 and Later

MS-DOS versions 5.0 and later use the /X switch to create the name cache in expanded memory instead of in conventional memory.

Modification Type: Major Last Reviewed: 5/12/2003
Keywords: KB39485