[comp.sys.apple] Disk Timing

delaneyg@wnre.aecl.CDN ("H. Grant Delaney") (09/02/89)

A new disk timer has been released.  I've uploaded to to listserv@brownVm
below are the docs for those interested


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                   DISKTIMER GS  v2.0



(C) 1988-89 Joe Jaworski
    All Rights Reserved.

DisktimerGS is FREEWARE. You may distribute it to anyone
without charge. There is no Shareware fee required. However,
the program is copyright material and is not to be
commercially distributed without prior permission.

DiskTimerGS and SCSI HACKER with complete instructions is
also available on disk from So What Software, 10221 Slater
Avenue, Suite 103, Fountain Valley, CA 92708. (714) 964-4298



Version 2.0 Update Information

1) Version 2.0 now includes Multi-Block READs. This test can
be used to optimize interleave of your SCSI drive for
maximum performance under GS/OS 5.0. The test performs 16
2000-block READ commands sequentially across the disk
starting with block 0000. The times reported are in seconds.

2) Minimum ProDOS volume size to run version 2.0 is 16MB.
Needless to say, DiskTimerGS cannot be run from floppies or
hard disks partitioned less than 16MB in size. DiskTimerGS
MUST be launched from the volume or disk to test.

3) Interrupts are now enabled during all tests. For
TransWarpGS owners, this allows you to maximize interleave
while your machine is accelerated. This also means that
moving the mouse, pressing keys, or accessing the Control
Panel during the test will give you dirty results. Any
Permanent Init files that hog interrupts on a frequent basis
will also distort the numbers.

4) If used in conjunction with THE SCSI HACKER, use the
Advanced Disk Utility from System 4.0 (not 5.0) to write
partitions, then run DisktimerGS under 5.0. This is because
the 5.0 native mode SCSI driver forces you to select 1:1 or
2:1 interleave ONLY, and then low-level formats your drive.
As always, use HDSCPartition after low-level formatting with
SCSI HACKER.

5) If you cannot see a difference in Multi-Block READ
results under changing interleave factors, chances are your
SCSI drive has either Read-Ahead buffering or built-in
caching. As a general rule, 6:1 interleave (5:1 with
TransWarpGS) yields good results with many hard drives under
5.0. With full cylinder caching, 1:1 will give best results.

6) All other tests remain the same as version 1.0.