[lug] RH Linux download + hdparm

[John Karns]

On Wed, 24 Oct 2001, D. Stimits said:

> John Karns wrote:
> >
> > On Tue, 23 Oct 2001, D. Stimits said:
> > I'm mystified.  The drive is a 68-pin Quantum Atlas V with active
> > termination, rated at 29MB/s, 7200rpm.  Must be the controller or mobo.
> > The machine is not process bound either (virtually idle), so I doubt that
> > the bus is i/o bound.  Although it could be a mobo design issue I suppose
> > - it's showing its age.  It would be interesting to read some performance
> > specs on those mobos.

Oops, the drive doesn't have active termination.  Rather, I
have an active terminator connected to the bus cable.


> What is the total capacity? I don't think there is such a thing as a
> 7200 rpm drive that can average 29 MB/s. They lied. Unless maybe it is
> one of those 180 GB drives. You'll get 31 MB/s with a 10k rpm 36 GB
> drive with reasonably dense clusters. Are you sure there is no fine
> print with some stipulation like "29 MB/s on outer tracks only, and
> unfragmented systems"? Sorry, I'm skeptical of any 7200 rpm drive that
> claims over 20 MB/s.

Capacity is 9.1 GB.  Specs from the Quantum site:

Exceptional value - 36.7GB, 18.3GB, and 9.1GB in a 1-inch-high, 3.5-inch
form factor.

Outstanding performance - 7,200 RPM, 6.3 ms average seek time, 29MB/sec
maximum sustained throughput, up to 160MB/sec bus transfer rate.


> You never need to worry about dma settings or cpu useage on scsi. Not in
> all cases, but in many, it plays nicer with the system as well. As soon
> as you add multiple devices to it, advantages show up real fast in
> comparison to IDE.

Another advantage is in having external devices, such as Zip and Jaz
drives, Tape, and scanner.  These can be used in various combinations and
connect easily to portables too.  Although in many cases one can get by
with the parallel port versions, they're a lot slower and in more
difficult to deal with both in terms of drivers and using multiple
devices.

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John Karns                                        jkarns at csd.net