🚀 go-pugleaf

Bob Cousins <bob@lintilla.demon.co.uk> wrote in article
<348abb65.10457046@news.demon.co.uk>...
> In demon.tech.pc, Butch Smith wrote:
> 
> >In article <34886102.16034927@news.demon.co.uk>,
bob@lintilla.demon.co.uk 
> >says...
> >
> >>>>Nope, the SCSI does bring a notable improvement.
> >>>
> >>>Care to back that up with some independently verified figures?
> >
> >
> >Here are some figures to ponder.
> >
> >My threadmark results and system configuration:
> >
> >Data Transfer Rate (MB/sec) was 9.37
> >Average CPU Utilization was 26.18 percent (using Adaptecs method of CPU 
> >usage for every Megabyte/second of data moved this is 2.79%. see 
> >--> http://www.adaptec.com/threadmark/ntcpubnch.html) 
> >Shuttle 603 mb with 1 meg L2 cache 66mhz bus
> >Intel P233mmx
> >128 megs 60ns edo ram 
> >Diamond Fireport40UW
> >Seagate ST34501W Cheetah 4.5gb, Umax scanner, Plextor cd-rom, and
Panasonic 
> >cd-r on the scsi bus
> >Running Windows NT 4ws with sp3 and IE4
> >Test was run on the second of three 1.42 gb partitions
> 
> Thanks for providing some hard figures, though your system is towards the
top
> end rather than typical. For comparative purposes its not very useful as
there
> are no 10,000 RPM EIDE drives (marketing reasons, rather than
technical?). Any
> performance benefit you see will be almost entirely due to spin speed
rather
> than a better interface.
> 
> Threadmark results don't mean much when running applications, try the
same thing
> doing an Access query for example.
> 
> However, your figures are interesting in themselves. On paper the ST34501
should
> achieve 11 to 17 MB/sec, average say 14 MB/sec. So you are getting 70% of
the


The sustained transfer rate of the Cheetah on the OD is 14MB/sec. 
Threadmark incorrectly attaches units of MB/sec to it's results; 
Threadmark's units are some kind of weighted average and are not comparable
to mfg's spec's sustained transfer rate figures.  Treat Threadmark results
as scalars that are comparable to other Threadmark figures and nothing
else.  The 9.37 figure for a Cheetah is the highest you'll find for any
single HD at least until in the next couple of days someone posts the
Ultrastar 9ZX figures.


> expected rate, which probably is quite good depending on transfer size. 
> 
> In practice you can only get the paper transfer rates if you use large
block
> sizes with sequential reads. In typical applications doing mixed
read/write
> random access, small transfers, the max transfer rate disappears quickly.
The
> limiting factors are seek time and latency.


The Cheetah does have superior access time to all other drives. 
Workstation performance is dominated by sustained transfer rate and not
access time.

Regards,

Ron Reaugh