🚀 go-pugleaf

In message <4gc5kc$cid@maureen.teleport.com> - jcorigan@teleport.com (John Corr
igan) writes:
:>
:>Message-ID: <4gc5kc$cid@maureen.teleport.com>
:>References: <4g3q25$2h5g@news-s01.ny.us.ibm.net>
:>Reply-To: jcorigan@teleport.com (John Corrigan)
:>NNTP-Posting-Host: ip-salem1-18.teleport.com
:>X-Newsreader: MR/2 Classic v2.26 - An OS/2 QWK reader
:>Xref: news-s01.ny.us.ibm.net comp.os.os2.setup.storage:4292 comp.os.os2.misc:98012 comp.periphs.scsi:32124
:>
:>In <4g3q25$2h5g@news-s01.ny.us.ibm.net>, iceware@ibm.net said:
:>
:>> The long story.
:>
:>> Using an adaptec 2940w or 2940UW, using our product IWSS I can bench a
:>>Seagate barracuda ST32550W out at between 6.9->7.2 MB when reading from
:>>cylynder zero for approx 80MB of data. Now if your drive is delivering
:>>the 5MB of data per second then the speedup is marginal, it would be
:>>better to have more memory, in order to reduce paging altogether. The
:>>only place where this falls apart is, when I state that our product
:>>benches the drive at that transfer rate, it is from reading the data off
:>>of the platters, yes, prefetch is still in use, but as the entire track
:>>is being read in one I/O, and the same track is never read twice, the
:>>drive is being forced to go back to the platters. Some disk benchmarks,
:>>are continuously hammering on the drives cache, which artificially
:>>inflates the numbers.  
:>
:>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 :)
:>
:>John Corrigan
:>CorrComp
:>
:>--
:>jcorigan@teleport.com (John Corrigan)
:>
:>
:>
:>... I use OS/2 2.0 and I don't care who knows!
:>-- MR/2 2.26 #314
:>
:>                                

 John,

 I don't agree, we build a lot of machines for OS/2 users, Developers, and 
vars. Using the ST31230N (Hawk), or the barracudas. The Hawk drives will come 
in around 4.5-5.0MB per second. Note when I am IWSS and relating these 
figures this is using IOCTL 9 (Which bypasses the file system of OS/2 
entirely, and all caches, because at that level one has access to the entire 
disk (just like FDISK)) to read 80MB of data starting at cylynder zero. 
Another way to look at it, is to compare the internal transfer rate of the 
two drives, not even close. Or yet a third way, is to just consider the RPM 
of both drives 5400 vs. 7200. The fastest drive we have ever benched was the 
ST12450W (Barracuda dual head), which yielded 9.0MB for 100MB, and a 
sustained DTR of 8.0MB when reading 1GB.

Jay Ice
Iceware Inc.