HDD Transfer Time?

Adam Dillaplain ( adam@calpha.com )
Thu, 17 Jul 1997 20:38:33 -0500

Hello All,

I just built a machine that has 10 9.1 GIG Ultra SCSI (wide) drives. They
are hooked to a PCI Adaptec 2940 Ultra Wide Controller and the integrated
motherboard equivalent (a 7880 if memory serves). Now here's my questions,

I thought I would write a batch file to test the horsepower of this
machine. The first file I wrote copied 52.5MB of files to each drive,
deleted them, and then copied them again in an endless loop. The total
time to copy all 52.5MB (~100files - the /winnt/system32 directory) was
exactly 37.2 seconds. That was with 3 instances of the file running,
staggered over different drives. How can this be? Is it holding the files
in cache and just spitting them out or what?

I then wrote a VB app that did the same thing except each time it finished
copying to the 10 drives it would spawn another copy of itself and start
over - so 2, then 4, then 8, then 16etc, etc copies were running. It
spawned about 250 copies of itself (ball parking here) and then crashed the
machine. Again, the orginal app made it in at about 37 seconds.

Can I expect this type of performance for real or is my test flawed?
Anyone know of a better way to test the time it takes to call a file and
write it somewhere else?



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