[Asus P4P800E-Deluxe] Can I make a RAID-0 array with unequal sized drives?

  • Thread starter Thread starter Shawn Barnhart
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Shawn Barnhart

Can I make a RAID-0 array with unequal sized drives using the Promise
contoller?

I can get away with this in the server/SCSI world with the caveaet that the
array can only be as large as the smallest drive; since I want to stripe a
40 and a 20, I'd only really get 40 gigs of striped space, 20 gigs of the 40
being lost.

I've RTFM and it doesn't say anything about size requirements.
 
Can I make a RAID-0 array with unequal sized drives using the Promise
contoller?

I can get away with this in the server/SCSI world with the caveaet that the
array can only be as large as the smallest drive; since I want to stripe a
40 and a 20, I'd only really get 40 gigs of striped space, 20 gigs of the 40
being lost.

I've RTFM and it doesn't say anything about size requirements.
Click to expand...

I think you can, but, for example, with one 80 gig drive and one 120
gig drive, the raid controller will only see two drives equal to the
size of the smaller drive, i.e., 160 gigs on your RAID 0 array.

Kevin Miller

"Either way, it is bad for Zathras."
 
I think you can, but, for example, with one 80 gig drive and one 120
gig drive, the raid controller will only see two drives equal to the
size of the smaller drive, i.e., 160 gigs on your RAID 0 array.
Click to expand...

And it works just that way. I tested it using a 10gig and a 20 gig Maxstore
and it let me make a 20 gig RAID-0 just fine (albeit losing the 10 gigs of
space on the 20 gig drive).

The downside? Way worse performance than my 80 gig SATA disk, and XP RAID
is about 25% faster than the Promise RAID using the same disks.

Promise: 14MB/sec write, 20 MB/sec read
XP RAID: 17MB/sec write, 24 MB/sec read
SATA single disk/no RAID: 48 MB/sec write, 48MB/sec read

I'm pretty sure I'm handicapped by the 10 gig drive -- its old and only does
UDMA2 according to XP device manager, and the 20 gig drive does UDMA5, per
XP devman. The Promise controller listed both drives as UDMA 2, perhaps
slowing the 20 gig drive to meet the 10 gig's max.

I might get better numbers once I swap the 10 gig for the 40 gig drive.
 
D said:
Just curious, but where are you getting yr read/write figs from?
Click to expand...

I used this program called "Nbench". It may well be wrong or misleading
info, but a back-of-the-envelope file copy seemed to reiterate its findings,
even if the specific numeric figures are incorrect.
 
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