By popular demand!  The following "Gospel of Caching According to Max" is
provided by Proportional Software based upon a great deal of OS/2 system
"tweeking" done by the DCF/2 development team.

You can get better performance from your system by using the memory you have
available to you in the most efficient and effective way.

From the table below, select the case that best describes the file system or
systems you use and memory available on your system.


 CASE 1:  You use
 only HPFS or only
 FAT but not both.                  HPFS only                         FAT only

 If system memory is at least:    Set CACHE: to                  Set DISKCACHE: to
                         16 MB         2048                             2048
                         12 MB         1536                             1536
                          8 MB         1024                             1024
 Set FAT DISKCACHE
 Parameters:
          LAZY WRITES                  N/A                               LW

 Set HPFS CACHE
 Parameters:
          LAZY WRITES                /LAZY:ON                           N/A
               MAXAGE                 >7,500                            N/A
             DISKIDLE                 60,000                            N/A
           BUFFERIDLE                 60,000                            N/A

 If your system is HPFS only REM out the DISKCACHE statement in your CONFIG.SYS
 file.  If your system is FAT only, REM out the IFS=HPFS.IFS statement.



 CASE 2:  You use
 both HPFS and FAT
 with                              HPFS active                      FAT passive

 If system memory is at least:    Set CACHE: to                  Set DISKCACHE: to
                         16 MB         2048                          512 -1024
                         12 MB         1536                          256 - 512
                          8 MB         1024                          128 - 256
 Set FAT DISKCACHE
 Parameters:
          LAZY WRITES                  N/A                               LW

 Set HPFS CACHE
 Parameters:
          LAZY WRITES                /LAZY:ON                           N/A
               MAXAGE                 >7,500                            N/A
             DISKIDLE                 60,000                            N/A
           BUFFERIDLE                 60,000                            N/A


 CASE 3:  You use
 both HPFS and FAT
 with                              HPFS passive                      FAT active

 If system memory is at least:    Set CACHE: to                  Set DISKCACHE: to
                         16 MB         1024                             2048
                         12 MB         768                              1536
                          8 MB         512                              1024

 FAT DISKCACHE
 Parameters
          LAZY WRITES                  N/A                               LW

 HPFS CACHE
 Parameters
          LAZY WRITES                /LAZY:ON                           N/A
               MAXAGE                 >7,500                            N/A
             DISKIDLE                 60,000                            N/A
           BUFFERIDLE                 60,000                            N/A


A few more notes:

     *   For purposes of the table above, "active" and "passive" are
         descriptors for the way a partition is used.  If it is seldom used, it
         is "passive."  If a lot of disk intensive I/O occurs on the partition,
         it is "active."

     *   The HPFS actually requires 128 to 130K of committed memory as opposed
         to the widely perceived 512K.  As cache size increases to 2MB, this
         requirement increases as well, up to a maximum of about 240K.

     *   The optimal cache size seems to be 1536.

     *   When comparing the relative merits of the HPFS versus FAT, consider
         the following:  On partitions of identical size, the HPFS gives you
         about 15% more space and performance is about 28% better!

     *   Instead of continuing to increase performance, a DISKCACHE value in
         excess of 2048 seems to degrade it.

We welcome your comments.  Reach us via email on CompuServe userid 71333,2765
or at Proportional Software, 1717 Linden Lake Rd., Ft. Collins, CO 80524, Tel.
(800) 666-4672 or (303) 484-2665.  Fax. (303) 484-2670.