Have you ever tried to use the XFS filesystem to access your
  (PC formated) ZIP Disks, and found it to be VEEERY slow!?
  I did, and recently I found the reason for this problem. I
  told the author of XFS about it - and hopefully we'll see a new
  and much faster XFS soon. Until then, XFSSpeedUp provides a
  partially workaround for the problem, increasing at least the
  reading speed.

  XFSSpeedUp only speeds up reading, the write accesses to the
  disk are still slow. It would be much more difficult to speed
  up write access as well.

  Without XFSSpeedUp, I have meassured a read/write speed of about
  20KB/sec with XFS and a PC formated ZIP disk. (My SCSI ZIP drive
  is connected to the UW-SCSI of my CyberstormPPC.)

  With XFSSpeedUp I have meassured a read speed of about 300KB/sec,
  that is about 15 times as fast! (But still not as fast as possible
  with a new XFS version!)

 PERMSSN    UID  GID    PACKED    SIZE  RATIO     CRC       STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
[generic]                 1632    2588  63.1% -lh5- 9e97 Aug  8  1999 XFSSpeedUp
[generic]                 1996    4486  44.5% -lh5- 67e2 Aug  8  1999 XFSSpeedUp.doc
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         2 files    3628    7074  51.3%            Aug  8  1999