🚀 go-pugleaf

John Kheit (jkheit@cnj.digex.net) wrote:
: 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.
: --

the benchmarks ARE a joke.  All they are for is the marketing dept.  Its 
kinda like the engine dynos in the car industry.  You go buy a race motor 
from some guy and he gives you this outrageous HP number.  well the dyno 
*did* see that number, but it was obtained by reving the motor up with no 
load and then turning on the dyno, like bringing your motor up to 7000RPM 
and then throwing it into gear.  Yes, you get the big HP numbers, but its 
a peak, not a norm. not to mention your motor just lost quite a few races 
off its life with  that kind of abuse.

so basically the bechmakrks (and dynos) are a good tool that are abused 
for a buck.
 --

Dave
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