Hi Markus

On Sat, 18 Jan 1997, Markus Baeurle wrote:

> Hi Chris!
> 
> In message <Pine.SGI.3.95L.970113160332.22385F-100000@tower.york.ac.uk>
>           Chris Gilbert <cg110@york.ac.uk> wrote:
> 
> > If a fast xfer rate is managed on RapIDE would this be the better medium
> > for baseing a news-server?
> 
> I'd still go for SCSI if I were you, especially now that Mark seems to be
> making progress wrt to the Cumana and Powertec drivers. For them it's probably
> a matter of finding a bug to get DMA transfers going while the RapIDE stuff
> still needs to be developed.

Point taken, but the present speed of SCSI is not as fast as the expected
first version of the rapide driver, and as Mark has actually purchased a
RapIDE it may be developed faster. 

> But that's not the only reason. SCSI is much more expandable for a large-scale
> application like a news server. People have suggested to use two 4GB drives
> instead of one 9GB one and it's not difficult to hit the IDE limit some time
> when you want to add more devices (not only harddisks). You will probably also
> need a backup medium, how do you connect this?

SCSI is more expandable to 8 devices, however you can fit 6 HD's in a RPC
with one card, 4 on the RapIDE card and 2 on the internal.

Would that much backup be needed, a news server expires news out, and can
catch up with a new feed.  Although it's possible to that certain files
will need backing up.

> Go for SCSI which is also a much more reliable thing IMHO because it's been
> more properly developed and tested by many years of use. It's not uncommon to
> get problems with different IDE harddisks connected to the same controller
> which is much more rare for SCSI.

It's not unheard of, but becoming less common, and if 2 drives were
purchased I'd expect that they'd both be the same.

In the short term using IDE will give more speed off the internal
interface, in the long term the speed will increase with drivers for the
rapide card.

For scsi in the short term the driver speed won't increase until dma (or
is it interupts) are done for SCSI.  In the long term scsi cards will
work, and you would be able to connect backup devices to scsi.  Scsi is
slightly more expensive I think.

I'm not sure of the track-records of either ide or scsi for reliablilty
but I never had a problem with IDE.

The question is do the people saying setup a newserver expect to see speed
initially out of the system, or are they willing to wait?


Chris Gilbert