RAID controller question...

[Mark Hahn]

> 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. 

the mass market has made lots of x86 hardware dirt cheap, "commodity",
and Linux and Beowulf are mainly (to me at least) about using this 
leverage for scientific programming.  the mass market has _not_ made
SCSI all that cheap, and definitely hasn't made RAID controllers cheap.
it _HAS_ made UDMA disks cheap, and the controllers are next to free.

the question is whether your Beowulf machine really needs to sustain
well over 20 MB/s, since it can do that on its builtin UDMA controllers.
if your needs are specialized (massive bandwidth, >68G/node, etc),
then you're getting out of the "leverage zone", and into a niche.

regards, mark hahn.