🚀 go-pugleaf

In article <2129@acf5.NYU.EDU>, liuyu@acf5.NYU.EDU (liuyu) writes:
>Hi,
>  I just bought a Wd Caviar 2200 hard drive. The Norton SI only shows about
>600k/sec DTR. But it showed over 1000k/sec DTR when I first
>installed it. Later it just dropped down to 600k.

Welcome to the confusing wonder of ZBR (Zone Bit Recording).  With modern IDE
drives, the number of sectors on a given track varies with its circumference.

The outermost cylinders have the highest sector density (and the highest
transfer rate since disk RPM is a constant (3600RPM for this drive, I believe).

Thus, if the test is being run on the outermost cylinders, you'll get the
highest transfer rate.  

Also note that the "CMOS" drive configuration (what the computer THINKS the
drive is configured as) and what the drive is ACTUALLY configured as (due to
"translation"), the test may be actually spanning multiple cylinders depending
on the data on the drive is organized.  In such a case you would have more
overhead due to the head repositioning (which the diagnostics program "thinks"
is not occurring due to sector translation).

Moral of the story:  Do not rely on disk benchmarks too heavily, as the way
they are measured can sometimes give widely varying results (particularly with
the use of on-drive hardware caches).

Alex

>The Checkit gives me 890k/s consistantly. I tried a different IDE card. And
>the same thing happened again. At first SI showed over 1000k DTR. But after
>running checkit which gave me 890k, SI dropped down to 600k. Even after
>rebooting, SI still gave me 600k.
>I was wondering if Norton SI or Checkit had bugs. Maybe one them change my
>CMOS setting (ie bus speed). But I doubt it because I checked my CMOS and
>there was no change.
>Is there any other small Benchmark programs that I can use?
>

Yes.  Try a recent version of CORE test.  It's pretty consistent ALTHOUGH it
sometimes gets confused by caching and reports very high performance (but
misleading) figures with some caches enabled.

>BTW, my machine is AMD386/40, 4meg, 64k cache, UMC chipset.