The price of a SAS disk drive (whether 2.5-inch or 3.5-inch form factor) is now higher than it will be in six, 12 or 18 months. If you need SAS drives today, go ahead and buy them.
For the moment, SAS probably won't make much of a dent into existing Fibre Channel drives at the high end, but expect to see Fibre Channel deployments be displaced by SAS in the mid- and entry-market price bands. This should happen up into the midmarket where the mix of performance and economy are best suited to SAS. For example, SAS drives may displace SATA drives in midrange network-attached storage (NAS) and iSCSI arrays. Effectively, SAS should appear in the middle of the market, moving up a little bit into the high end to displace Fibre Channel and down into the low end where it coexists well with SATA.
I expect to see a lot more of SAS technology in the near future. It's showing up in blade servers and traditional servers. SAS is also appearing more in iSCSI storage. The real growth area is in 2.5-inch SAS drives for their high-density and lower power consumption, and the SAS controller's compatibility with SATA drives where both drive types can operate together on the same controller.
Go back to the beginning of the Disk Hardware FAQ Guide.