On Fri, 2006-12-01 at 08:37 +0000, Andrew Back wrote: > On Fri, 1 Dec 2006, Kyle Gordon wrote:
> > > > Caviar 80GB (Master) + DiamondMax 60 (slave) on the internal IDE controller > > + > > Deskstar 120GXP on a PCI Ultra100 TX2 card - giving 120GB > > What configuration gives 120GB from 80 + 60? Is it not multiples of the smallest drive? Like (n-1)x, n being number of drives and x being the capacity of the smallest drive? > > > Am I wrong in thinking that the SCSI drives will be faster than the IDE > > setup, > > given their age? The DiamondMax is ATA66 whereas the Caviar and DeskStar are > > ATA100, but the Quantums are Ultra160. The Quantums however, are older, and > > the primary use of this will be ~, where random access will be preferred > > over > > sequential streaming. > > It may not be the case any more given advances in IDE/ATA technology but > it certainly used to be that all other things being equal SCSI would win > where the workload was of a more random nature. It's bus protocol is > (was?) more advanced and allowed command queueing. The OS could send > a bunch of requests at the drive and it would be able to service them in > the order it saw fit based on where the heads where at. Whereas with IDE > everything was serialised and the drive would have to wait for the blocks > to pass the heads, service that request, and then take another request, > wait for the data to go by the heads and so on.. So SCSI made sense in > file servers and multiuser systems, and IDE in the likes of a video > editing workstation where access would be largely sequential. > > Of course then you have to factor in drive the performance, cache and so > on. And overhead/benefits of disk configuration options - RAID*/JBOD. > > There may be other benefits to SCSI I've missed, and I admittedly know > little if anything about modern ATA drives. I think that settles it then... SCSI it is :-) They may be old, but still more advanced. On the plus side, it frees up some drives for use in other machines :-) Cheers, Kyle _______________________________________________ Scottish mailing list [email protected] https://mailman.lug.org.uk/mailman/listinfo/scottish
