> From: Leonard Zhang System Administrator ISD RVIB
<[EMAIL PROTECTED]>
> To: Alan Cox <[EMAIL PROTECTED]>
> Date: Monday, December 07, 1998 12:01 AM
>
> On Sun, 6 Dec 1998, Alan Cox wrote:
>
> > > I think currently spinning SCSI hard disks on the world, either in
servers
> > > or workstation, either in Unix/Linux or NT, is 50-pin old guys, no
DPT disk
> >
> > And as my stats showed for real work even old 5400 rpm fast scsi on a
> > now discontinued adapter (the BT946) beats current UDMA IDE for real
world
> > compiles. You "think". I've "measured"
> >
>
> Open server 5.0.4p, DPT RAID-1, 32 MB cache, PCI, 4.2 GB (A cable)
>
> copy 9,177 K in 9 seconds.
>
> Red hat 4.2, 8 GB IDE
>
> copy 9,397 K in 2 seconds.
>
> both run in shell script.
Comparing OpenServer 5 vs. Linux is a pretty unfair comparison, OpenServer
disk access would be slower even on a ramdisk :) <jk - sort of> Unless you
disabled it, OS5's filesystem does transaction logging, making it much
slower than a normal filesystem. We compared a 36 GB, Cheetah standalone
RAID on OS5 with a Microp. SCSI whatever on Linux, and the Linux box
severely outperformed the OS5 box. If you turn off SCO fs stuff, it will
considerably speed up (although it will get really happy if your box ever
dies in the middle of a run:) You may also actually have the RAID slow
your transfer down since it must perform multiple writes of the same data.
We're definitely comparing Apples and Bicycles here.
I believe you also missed the point of the previous posts. IDE/SCSI on a
streaming file (i.e., copying a 9MB file) they tend to have similar times.
It's when you have several drives transferring data, or when you have a
drive doing several operations (especially w/ lots of seeking) that SCSI
kicks IDE's butt. These tend to happen a lot in the real world, and is the
reason for the general advocacy for SCSI.
I would have to concur with the idea that there are not many 50pin SCSI
setups out there. Of course, I cannot speak of anything less than Ultra
SCSI at the office -- since we don't have any. Nor do I have anything Less
than UW at home, nor do any of the several friends and organizations I know
of running SCSI. Altogether we're talking about 15 systems. I just don't
know anyone who uses anything less. I really don't know anyone using RLL,
MFM, or the original IDE either though :)
In closing, <G>
I would like to mention that Leonard asked a ? earlier... This is not a
flame, or anything of the sort, but simply an answer. To multiple posts:
Generally the reply goes to the mailing list as well as to the original
sender for various reasons. Also if the mail has been sent to several
lists and they reply to those lists, AND you are on those lists, you will
appear to receive multiple posts. Really it was just single posts to all
the right places.
Hope we're clearing stuff up for anyone confused by all this :),
Brian Geisel
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