🚀 go-pugleaf

In message <4gfmnp$ful@clarknet.clark.net> - gtaylor@clark.net (Glynn C Taylor)
 writes:
:>
:>Peter Stein (nbi@xnet.com) wrote:
:>: In article <4g3q25$2h5g@news-s01.ny.us.ibm.net>,
:>: Herbert J. Ice Jr. <iceware@ibm.net> wrote:
:>: >In message <4g2d0n$7pm@usc.edu> - dywilson@scf.usc.edu (Donald Wilson) writes:
:>: >
:>: > Donald,
:>: >
:>: > The short story, go for the extra memory.
:>: >
:>: > 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.  
:>: > 
:>: >  At this time SCSI-3 is not an adopted standard, yes it is being used
:>: >in marketing hype, but that is the only place. As to UltraWide drives, 
:>: >well first someone must find them. Note that on the Adaptec 2940UW, the ultra 
:>: >wide abilties are disabled in the controllers firmware by default, as there 
:>: >are so few drives out there right now that are ultrawide.
:>: 
:>: Excellent point. In fact in the March Computer Shopper I couldn't find any
:>: UW drives advertised.
:>: 
:>: Peter Stein
:>: nbi@xnet.com
:>: 
:>I have a scsi-3 controller (fast-wide ncr825 based pci from tyan) and the 
:>following company sells both scsi-3 controllers and disks (conner):
:>Corporate Systems Center
:>1294 Hammerwood Ave.
:>Sunnyvale, CA 94089
:>408-734-3475
:>
:>The controllers run in os/2 and suport scsi2 and scsi3 disks.  I have not 
:>benchmarked them for speed yet, but they seem at least as fast as my 
:>pio-4 and pio-3 eide disks.  The disks are available in 1050 and 2.1 gb 
:>sizes.  The 1 gig drive is $259.  They have a web page, but I can't 
:>recall the url, sorry.

 Glynn,

 I have a controller here that touts to be Scsi-3 (Qlogic), but I'll be 
darned if I can find anything Scsi-3 about it. Does it support wide Scsi 
drives? Yes, but then 16 and 32 bit wide data transfer paths are defined in 
the Scsi-2 spec. Does it support Synch transfer? Yes, also defined in Scsi-2. 
Does it support any of the new cabeling defined in Scsi-3? No. About a year 
ago, there was a brief blip of Scsi-3 coming out, when I took a look into it, 
all they were doing was implementing some of the PROPOSED features of Scsi-3, 
in the drives firmware (Such as the number of cache hits in the drives 
cache). It's mighty difficult to be compliant with a specification, when the 
spec is not ratified.

Jay Ice
Iceware Inc.