rs79.vrx.palo-alto.ca.us
Notes on SCSI RAID Controllers
Notes on SCSI RAID Controllers
Circa 2007

IMG_6942t.jpg
Mylex 1164P
xs sm med lg
IMG_6943t.jpg
IBM Serveraid 4
xs sm med lg
IMG_6944t.jpg
DAC 960P
xs sm med lg
IMG_6946t.jpg
DAC 960P
xs sm med lg
IMG_6948t.jpg
AMI 428
xs sm med lg
IMG_6949t.jpg
AMI 428
xs sm med lg

I seem to have about 3 flavours of RAID cards around this place, all SCSI. 1 IBM ServeRaid 4. Slick little beast and probably my favorite. U160. I also have a few AMI 428 cards and Mylex i960 cards most of which have several channels. The AMI's and IBM have 1.

Using a 9G Maxtor drive I restored a disk image from another drive onto the 9G. Norton Ghost got a throughput of 1000 Mb/S and took 4:58. Restoring to a Raid0 (striped) array of the same 9G drive got a throughput of 666 Mb/S and took 7 minutes.

But, running under Windows XP and copying a 2.4G file took 2:25 to the 9G drive and 1:45 to a striped array of two of the same 9G drives. All SCSI busses are LVD 80mbit.

I'd expected it to be a it faster than that. Hrmph. So, SCSI RAD is faster than SCSI but it's not twice as fast.

But now I have a system that will load Opera in a mere fraction of a second. Of course with six spindles, 3 cables and a 15 year old raid controller the mean time between failures is like "Tuesday". But I have spare drives and controllers and cables...

Richard sexton 2007


SSD drives have rendered SCSI RAID almost moot, although it still has it's place in certain niches. One of the most practical these days is replacing the glacially slow old IDE drive in 10 year old computers with a cheap RAID 0 subsystem or hey, go completely crazy and add one for swap as well.

This transforms a computer that can't get out of its own way into something you can use to drive a 1080P system, despite the huge files involved.

Cheap RAID controllers are $5 all day on ebay and small drives are about the same. Until SSD drives drop to $15 (which will happen, despite this being unthinkable at the current writing) this is still one of the better ways to breath life into a (sometimes very) old system.

Richard Sexton 2013