🚀 go-pugleaf

jcorigan@teleport.com (John Corrigan) wrote:
> I recently benched a 2940 with a Seagate Hawk (2GB, 5400RPM,
> SCSI2-F) and it showed transfer rates of 6.7MB/sec for both reads
> and writes for file sizes up to 4MB.  (The benchmark creates the
> file and times the write speed and the read speed, the tests were
> done with no software disk caching).  Sounds to me like there
> isn't much of a benefit to going to SCSI2-UW :)

Under most DOS benchmarks I get rediculous read/write performance
reports.  My barracuda also gets around 6.7m/sec (and its not wide
or anything)...  Under NeXTSTEP (i.e. Unix variant) and using IOzone
(an excellent benchmark, don't know if it exists for other OS's)
I get more accurate reports around 2m/sec.

IOzone simulates real world read/writes, and is careful to make
the test file big enough so there are no secondary memory caching
effects.  I.E. if you have 32megs of RAM and you use a test file
of only 8megs, odds are that significant portions of it will be
cached by the system.

Most DOS apps are worse yet, in that they send single blocks (yes
sequential, but they still get cached by the system) of X size
(maybe 64k, which is nothing).

That's why you see such great disparity between the 'make me feel
good benchmarks' and the real world file copy times.
--
Thanks, be well, take care, later, John Kheit   )^>   %^)   =^)

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