RAID controller question...

[Joel Jaeggli]

On Thu, 10 Sep 1998, Bill Broadley wrote:

> On Wed, Sep 09, 1998 at 10:12:42PM -0700, Joel Jaeggli wrote:
> > 
> > Up to a point. You don't increase your perfromance when you have more than
> > one ide disk per channel. since only one can have the bus at a time and
> > the controler can't have more than one operation pending a time. scsi
> > controllers can regularly have as many as 24 pending read write operations
> > per channel.
> 
> Right, but you can only have one pending (usefully) per scsi device.
> And additional EIDE controllers are cheap.

pci slots aren't though. By way of example I have a tyan 1668 dual ppro
running as my nfs server, it has five pci slots which is more than most of
the intel manufactured ppro boards but not as many as the tyan 1836, so
with two 10/100 nics, a video card, and a scsi controller, I have on free
slot left.  currently I have six scsi disks plus a dat drive. Since the
dat drive requires a scsi card, I could only put a total of 4 ide disks in
the machine, one in each controller on the motherboard, and two hanging on
an ide controller in the remaining pci slot, if I wanted optimal
performance out of each ide channel. 

joelja

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Joel Jaeggli				       joelja@darkwing.uoregon.edu    
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