🚀 go-pugleaf

Speaking of speed and not being particularly familiar with the SCSI
protocol, my common sense tells me that having a stripe on a IDE
multichannel controller can push the speed quite some way..
Again my common sense tells me that a SCSI controller can not stream data
from more than one drive at a time, as only one drive can put data on the
bus at the same time
We have an experimental machine with a six way IDE controller with 128 MB on
controller cache with six 40 GB, set as a stripe. This is solely as a work
drive, as there is another drive on the main controller as system drive and
yet another one for swap only, each on it's own channel.
We have simulation software running on it, the machine is a dual AMD with 2
GB memory. It appears that running the model from the stripe makes the
system fully utilize the processing power, while running from a separate
drive shows clearly a bottle neck in the HD data transfer. Our consultants
love the machine because it performs the simulation about 3 times faster
than their laptops (2.6 with 1 GB RAM).
The 2.5" drives in the DELL laptops are pathetic. Using an external 3.5"
HD - firewire makes the system crunch the models about 50% faster. I have
also purchased a 7200 8MB 2.5" and replaced a 4500 (standard on DELL) but
the consultant using it found no gain from that (even a 5% decrease in
speed!!!) which I can not explain.

As mentioned in another mail when using hardware RAID (of any kind) I
strongly recommend refraining from converting the volume from "basic" to
"dynamic"; Promise controllers have the ability to use a drive as "hot
spare" but if you convert to dynamic and the RAID tries to switch on the
spare you will probably lose the data!
I am not too sure if this is the case for SCSI as well but I have added
another HD to a SCSI system and I can not make the spare to join the RAID
volume, I suspect is because the volume has been made dynamic previously. I
should probably read more about it but time is at a premium for me.

Anyway, I thought it would be good to share this information with the people
reading this newsgroup.
And all (decent) comments are most welcome

Cristian Croitoru

"That Guy" :
> Agreed.  Using SCSI drives on a home system is like chartering an airplane
> to take you across the street.  IDE drives are fast enough and reliable
> enough, especially with the security of RAID 5.  SCSI drives might be a
few
> percent faster, but can cost more than twice as much.
>
>