Re: Rory, are you trying to break a record here?

Hello Francois and Rory:

I'm a little skeptical about Rory's setup: How did you attach 16 SATA II PTP drives to the system? Also the OS striping isn't very efficient - on our RAID controllers at NAB, we have a single PATA array of 10 drives 500MB/sec - in fact, we have a single array of 40 2.5" SATA-1 drives doing 1.5GBytes/sec (2GBytes/second internal transfer rate). Unless the controller Rory is using does hardware striping, there is a sector transfer buffer in Apple Disk Utility which is 7.5K, and a stripe set of more than 7 physical drives will probably fail. The overhead of the striping is taking it's toll - assuming he used Seagate 300GB drives - the drives have an internal transfer rate of about 60MB/sec on reads and 55MB/sec on writes - That means he has an internal transfer rate of over 900MB/sec, and is losing nearly half the speed in the software striping. In our 40-drive unit, we are doing 1.5GBytes/sec -- the only reason we aren't closer to 2GBytes is the host adapter maxes out at 1.6GBytes/sec.


Lance Gropper
Ciprico