Date:  Tuesday, April 2, 1996 10:27:48 AM
Author:  Apple Computer, Inc.
Subject:  Disk I/O Performance Tools

Equipment:  Macintosh

Summary:  SCSI Monitor and IOTracer are performance tools designed to 
record and report information on file system and SCSI performance in a 
Macintosh environment.  This release includes bug fixes for System 
Software 7.5.3 and PCI-based Macintosh systems.

     SCSI Monitor reports aggregate information on disk I/O. It reports 
the number of disk reads and write operations performed, the number of 
sectors involved and the time taken to complete the operations. 
IOTracer collects trace data on file system and driver reads and writes 
and other I/O related calls. An analysis tool is provided which inputs an 
IOTracer trace and outputs a summary of the I/O performance. IOTracer can 
also collect data on resource calls, which can give insight into the 
effect of application/system resource requests and disk I/O performance. 


     The information provided by these tools can provide an understanding 
of an application's disk I/O behavior and interaction with the system. It 
is also useful for tuning an application with respect to disk I/O 
performance. A disk I/O test program called 'BlockReader' is also 
included.

Requires: System 7.0

Keywords:  SCSI, Disk I/O, Performance
Virus scan:  Disinfectant 3.6 shows no viruses in this file