Arrays, and for two reasons:

1) Mirroring requires CPU cycles to manage and synchronize disks (this is
on top of normal disk delays including disk speed, SCSI I/O functions and
contention, etc).  If you ever are short on CPU then mirroring overhead may
become a problem.

2) Many arrays come with significant RAM caches and can reduce I/O time by
avoiding disk reads/writes.  Large caches can be found on single drives,
but it is fairly rare.

3) Also, the last time I checked, mirroring was not supported for the
system volume set.  Since transient I/O can be significant, and since
redundancy for the system volume set is highly desirable, you'll likely end
up with one set of arrays anyway.

On Friday, October 31, 1997 6:16 AM, Pedro Gonzalez
[SMTP:[log in to unmask]] wrote:
> We have a 987SX that is having some disk bottleneck problems.  Most of
our
> disc drives are older single ended drives and we want to replace them
with
> newer Fast/Wide discs and io cards and get some redundancy at the same
time.
> I have heard conflicting stories on using disk Arrays Vs regular FWD
drives
> that are mirrored.
> Does any have any experience in which solution is better for disc
> performance?
>