[comp.sys.apollo] Internal-external SCSI disks

cmb@GARNET.BUCKNELL.EDU (Christine Miller Buffinton) (06/10/91)

I would be very appreciative of information anyone could provide
regarding comparison of internal and external SCSI disks.  We 
need to purchase a new file server to expand storage on our 
network of 40 workstations.  The machine must have an ATR 
connection, so the 425e is out of the question. The 425t with 
1.3 GB of external storage and the 425s with 1.3 GB of internal 
storage are two possibilities.  The first option is $7,000 (list) 
less expensive than the latter.  Does the internal disk have
any clear advantages in terms of file access time or other 
characteristics pertinent to how the machine will function as 
a file server?  In other words, is there any good reason to 
spend the additional money?   


Christine Buffinton
Director, Center for Computer-Aided Engineering and Design
Bucknell University  
cmb@apollo.bucknell.edu

thompson@PAN.SSEC.HONEYWELL.COM (John Thompson) (06/11/91)

> We need to purchase a new file server to expand storage on our 
> network of 40 workstations.  ...  The 425t with 
> 1.3 GB of external storage and the 425s with 1.3 GB of internal 
> storage are two possibilities.  The first option is $7,000 (list) 
> less expensive than the latter.  Does the internal disk have
> any clear advantages in terms of file access time or other 
> characteristics pertinent to how the machine will function as 
> a file server?  In other words, is there any good reason to 
> spend the additional money?   
I don't know the SCSI speeds between internal and external buses
on the 400 series, but I can only see three reasons for getting a
425s rather than a 425t --
o   You need the fast graphics from the Personal Visualization System.  This
    may actually be a moot (mooter?) point with the new CRX displays.
o   You need the [E]ISA-bus for peripherals.
o   You need to hang an ungodly amount of disk space off a single-point-of-
    failure node.  You can put about 9 GB of disk space on a 425t node, and
    with extran controllers, you can put about 27GB on a 425s node.  IMHO,
    anyone who hangs more than 10GB on a node is asking for failures.

-- jt --
John Thompson
Honeywell, SSEC
Plymouth, MN  55441
thompson@pan.ssec.honeywell.com

When in danger, when in doubt --
run in circles, scream and shout.