🚀 go-pugleaf

In article <475nuh$45n@noc.tor.hookup.net>, Richard Whitehouse
<cvanderb@toronto.cbc.ca> wrote:

> >If you are looking for an Ultra SCSI 3 drive (Fast 20) then, you'd
> >first need a Fast-20 SCSI adaptor (like an Adaptec 2940UW).  Two of
> >the best 2 GB Ultra SCSI drives are the Seagate Barracuda 4LP
> >(ST32171) and the Quantum Atlas II (XP32181).  Add "W" to the end of
> >the vendor part numbers if you need an Ultra Wide drive (40MB/sec).
> 
> These numbers that you mentioned (20MB/Sec and 40MB/sec) are not
> sustained-throughput rates, I just wondered whether you were aware
> of that.  They are probably burst-mode rates, or perhaps they are
> the maximum capability of the bus.  Some manufacturers like Seagate
> do not like to tell you what their sustained throughput numbers are,
> they would rather mention burst-mode numbers because they sound more
> impressive.  Micropolis are at least honest enough to tell you what
> their real sustained throughput rates are.  Be aware that these 
> drives will not be capable of sustained throughput *anywhere near* 
> those numbers.  The sustained throughput will probably be somewhere 
> between 5MB/sec and 10MB/sec.

You're correct the 20 and 40 Mbyte/sec numbers are burst rates
for Fast-20 Narrow and Wide, respectively.

The sustained performance is no mystery.  Just look at the
'Cuda 4LP's specs <http://www.seagate.com/sales/cuda/cuda4lp.html>
where it states (on the first line no less) that the data rate 
ranges from 75-120 Mbits/sec.  That roughly translates to 7-12 MBytes/sec,
sustained.

CP