On 10/30/06, Greg Wallace <gregwallace@fastmail.fm> wrote:

Could one of you gurus give me a brief description of what it means to have a SATA-SAS Integrated card in a computer? I assume this somehow allows you to link a SATA drive to a SCSI drive in your machine, but I don't understand what that does for you.

Thanks, Greg Wallace

Greg, It means the SATA//SAS controller can talk natively to either a SATA drive or to a SAS drive. You buy the one you want and plug it in. Details and background for the bored: I assume your aware the TCP/IP traffic can be sent over various media (ethernet, dsl, T-1, E-1, wireless, etc.) That is because a layered approach is taken in a lot of communication systems. The 7-layer model even formalizes it.

From the opposite perspective a T-1 can carry channelized voice (traditional usage), channelized data, or unchanelized data. The data is what can be treated as IP packets.

Now in the disk drive world previous to 1990, this was not really true. An IDE cable was used exclusively to carry a predefined set of disk drive commands. And the command set was hardwired into the drive electronics. SCSI was a little better back then in that a small embedded cpu was on the drive to act as a command interpreter. This allowed the main CPU to offload the work to the SCSI embedded cpu. Things have advanced significantly since then. Now a highly layered approach is being taken by both ATA and by SCSI. ATA now supports PATA and SATA (Parrellel & Serial) SCSI supports a whole host of connection types (Parrellel SCSI (in multiple viersions), Fibre-Channel, iSCSI, USB, Firewire) and even an IDE cable is used for ATAPI. (ATAPI uses SCSI commands across the IDE cable) Fortunately when ATA and SCSI decided to implement a high-speed serial connection / media (SATA/SAS), they choose to use exactly the same one. Thus the cable a lot of us call a SATA cable could just as easily be called a SAS cable. So te designers of a disk controller that supports the new cabling have 3 choices: SATA only support SAS only support Both SATA and SAS support Hope that helps Greg -- Greg Freemyer The Norcross Group Forensics for the 21st Century