On Wed, Oct 1, 2008 at 12:51 PM, Joerg Schilling < [EMAIL PROTECTED]> wrote:
> > Did you recently look at spec files from drive manufacturers? > > If you look at drives in the same category, the difference between a SATA > and a > SAS disk is only the firmware and the way the drive mechanism has been > selected. > Another difference is that SAS drives may have two SAS interfaces instead > of the > single SATA interface found in the SATA drives. > > IOPS/s depend on seek times, latency times and probably on disk cache size. > > If you have a drive with 1 ms seek time, the seek time is not really > important. > What's important is the latency time which is 4ms for a 7200 rpm drive and > only > 2 ms for 15000 rpm drive. > > People who talk about SAS usually forget that they try to compare 15000 rpm > SAS drives with 7200 rpm SATA drives. There are faster SATA drives but > these > drives consume more power. > That's because the faster SATA drives cost just as much money as their SAS counterparts for less performance and none of the advantages SAS brings such as dual ports. Not to mention none of them can be dual sourced making it a non-starter in the enterprise. --Tim
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