Step rate change (WD2010) Some Benchmarks ... (was Re: WD2010 / No ECC)

[Clarence Dold]

in article <947 at icus.islp.ny.us>, lenny at icus.islp.ny.us (Lenny Tropiano) says:
> (Clarence Dold) writes:
> ...
> |>Try setting the Step Rate in an iv.desc file to 14 instead of 0, 
--------

> Ok, call me brave, but I had to try it...  It sorta was a test for my WD2010
> anyhow.   I have another UNIX pc (icusdvlp) that I use for such occasions,
...
> # /bin/time /bin/dd if=/dev/rfp002 of=/dev/null bs=100k
...
> # iv -dv /dev/rfp000 > HD.desc
...
> # /bin/ed HD.desc
...
> # iv -uv /dev/rfp000 HD.desc
...
> # /bin/time /bin/dd if=/dev/rfp002 of=/dev/null bs=100k

Okay, so we've established that the system doesn't die with a Step Rate of 14.
Copying from one slice to null is a test of single cylinder seeks.
What we want is timing of multi-cylinder seeks.
I forget which slices are which on the 3B1...

/bin/time /bin/dd if=/dev/rfp000 of=junkfile.on.outermost.slice bs=8k

will tell us the most about multi-cylinder seeks.
Copying from slice 0 to slice 3(?) will give us an arbitrarily large seek,
but it will show the speed difference, if there is one.
bs=8k will read just one track at a time.  We're not interested in 
buffering efficiency, just seek times.

Another test, that I'm not sure is available on 3B1 Diags, would be to start
the 'Random Seeks' test, which on other Convergent machines is 1000 seeks.
Timing this with a watch will show how many seconds for 1000 seeks,
or how many milliseconds/seek the drive will do under Diags.

Again, although I work at Convergent, I never had anything to do with the
3B1, except as a guest speaker on Modem and Phone Control, which was an 
odd subject for me to teach to the phone company.
-- 
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Clarence A Dold - dold at tsmiti.Convergent.COM		(408) 434-5293
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