textfiles/apple/DOCUMENTATION/disktimer

DISKTIMER GS

A Hard Disk Benchmarking Program



(C) 1988 Joe Jaworski
18405 Tamarind Street
Fountain Valley, CA 92708
                                       GEnie: JVJAWORSKI
                                  CompuServe: [73307,310]


This program is FREEWARE. It is copyright material but you
may use it and/or distribute it free of charge to anyone for
personal, non-commercial use.  Licensing is required for
including DiskTimerGS with any commercial hardware or
software product.  Contact me at the above address for
licensing information.



What is DiskTimerGS?

DisktimerGS is a "Benchmark" or performance rating program
designed to measure how efficiently a hard disk drive will
perform on an Apple IIGS. It is designed to give you, the
consumer, a rating system by which to measure the
performance of hard disk drives and their manufacturers
claims.

Like all benchmarks, test results cannot be strictly
correlated to a drive's performance in an actual
application. However, the key to a benchmark is the
comparison of results between different products.

DiskTimerGS has been designed to eliminate as many system
variables as possible to insure accurate results in a wide
variety of system configurations. DiskTimerGS is immune to
disk cache settings, controller cache memory, partitioning,
system interrupts (including mouse movement), and buffered
drive seeks.

APPLETALK USERS: DiskTimerGS disables interrupts during the
actual test periods. This will "hang" the network.
Disconnect AppleTalk before running DisktimerGS.



Using DisktTimerGS

DiskTimerGS is very easy to use. Simple transfer a copy of
the program to the disk drive you want to test and launch it
from there. It doesn't matter if the program is put in a
folder or in the root directory. However, it must be
launched from the drive you want to test. The tests will
take anywhere from 2 to 5 minutes to run.

DisktimerGS does not perform any WRITE operations and will
not alter any data on any disk under test. In fact, the disk
must be formatted and contain a ProDOS directory in order to
run the tests. If the disk is partitioned, any single
partition can be tested (the results are independent of
partitioning) but the partition selected must be at least
9.9 Megabytes in size in order for the tests to run. DO NOT
try to run DiskTimer from a floppy. It won't work.



About the Results

DiskTimerGS reports its results in seconds for each
operation. The three tests performed are:

READ Timing: This test performs a sequential READ of a
number of 512 byte blocks to determine how fast the Hard
Disk can transfer consecutive data. The factors that most
effect this number are the Disk Interleave and Data Transfer
rate of the drive.

SEEK Timing: This test measures the time it takes to seek
the R/W heads of the drive across 10 Megabytes of data. The
results of this test are mainly governed by the
Track-to-Track, Average Access, and Head Settling time of
the drive.

ADAPTER Timing: This test performs a repeated READ of a
single block on the disk, measuring the overhead to receive
data from the low-level disk interface through the ProDOS 16
high-level interface. Factors that effect this rating are
the delays through the Host Adapter Card originating at the
disk drive interface hardware and the Disk/Host interface
firmware. In other words, it measures the efficiency of the
SCSI Card or other controller Card used to operate the disk
drive.


Interpreting Results

Compare your drive to the others listed in the DiskTimerGS
comparison list (included in this download) to see how well
your drive has performed.



Submitting To the Comparison List

The DiskTimerGS Comparison List included with this download
will be frequently updated. To make DiskTimerGS an effective
tool, I need your help in keeping this list as up to date as
possible. If you have a hard disk drive that is not on the
list, run DiskTimerGS and submit your test results so I can
include it in the next update. Even if your drive is
"Homebrew", it would be interesting to compare results to
commercially available products.

Run DiskTimerGS at least three times (The results may vary
slightly depending upon the drive/controller tested). Submit
all three test results (or an average of the three) along
with your name, BBS ID, and any additional comments to
support the test setup. Submit your data to one of my BBS
ID's listed above.

Thanks for your support. I hope you find DiskTimerGS an
Independent and valuable aid in selecting one of the growing
number of hard disk drives now available for the IIGS.

-Joe Jaworski
















DiskTimerGS operates through the ProDOS 16 interface under
GS/OS. It is not compatible with System Disks before version
4.0 and is not compatible with other models of the Apple II