>
> Mime-Version: 1.0
> Content-Type: text/plain; charset=us-ascii
> Date: Wed, 12 Feb 1997 18:42:40 -0500
> From: Travis Woodbury <travis@rwii.com>
>
>
> > [snip]
> > > Again, on the performance side, I get upwards of 25MB/s on either of my
> > > Seagate UltraWide scsi devices; a measurement that you are very unlikely
> > > to see on _any_ IDE drive (note: this is while the system is under
> > > considerable load, too).
> > >
> >
> > How did you measure that 25MB/s ? My 2 Maxtor IDE 2.0G's give me an
> > 'hdparm -T' value (cached xfer) of 32.0MB/s on a Micronics PCI/IDE
> > M54HI-Plus with a iP200 cpu. (My 'hdparm -t' >4.0 ie non-cached xfer) :-)
>
> Whats the cached transfer rate matter. Its the overall throughput that
> matters.
>
> With a Buslogic BT-958 and a Seagate Barracuda (ST32171W) I get just over 8.5
> MB/s
> with hdparm...no, thats not the cached rate. Unfortunately it didnt come cheap
>
> BT-958 $241
> ST32171W $695
>
> IDE seems to be the right choice for the everday workstation. I get great
> throughput
> with the Quantum Fireballs 6.50 MB/s. $252
>
> But for a small server or heavily used work station an Ultra Wide bus of fast
> drives
> kicks ass.
>
> One of these days I'll have find the time to stripe two of those ST32171W's:)
>
> Not that this affects kernel development:)
>
> -Travis Woodbury
>
>
>
Could it be that you are confusing MBytes with MBits ?
'Cause even with PIO mode 4 an EIDE bus cannot exceed 16 MBytes/sec
regardless of where the data comes from.
Furthermore, according to my sources there is no no SCSI HD which
exceeds 10 MBytes/sec real transfer (fram disk not cache) despite
having the theoretical limit of 40 MBytes/sec for an UltraWide controller.
CR.
-----------------------------------------------------------
| Christian Rienecker Tel. : +49 40 8998-2926 (Office) |
| HASYLAB at DESY -2368 (Lab) |
| Notkestr. 85 Fax. : +49 40 8998-2987 |
| 22603 Hamburg E-mail (Internet) |
| Germany : RIENECKE@desy.de |
-----------------------------------------------------------