On Mon, Jun 20, 2005 at 04:01:20PM -0400, Nathan Dragun wrote: > So, why not get SCSI that supports the same thing?
SATA drives are much bigger, often have higher transfer rates (although slower seeks too in general compared to 15k drives), have nicer cables that don't block airflow, cost much less as does the controller, and a nice scsi raid card also costs much more than an SATA hardware raid card. With SATA hardware raid you get much more space and usually more speed for a lot less money. > Ah, didn't know about that one actually, havn't researched SATA drives > being manufactured in a while. Up until the last 6 months or so they were all using IDE to SATA converter chips instead, but now they are doing native SATA instead. > Thats what SCA is for. Easy to adapt into any SCSI system even if it > does not defaultly support SCA with a $5 adapter. I've never had a bad > drive ever take down the channel. Well if that works, that's good. It wasn't part of the scsi spec itself. Anyone putting two drives on an ide connector are also asking for trouble of course while one per cable is fine. > So you've got my interests in SAS. What kind of system is it exactly? > Targeted market? Compatibility? Expected release? I'm thinking a search > on google for 'SAS' would give me a lot of what I'm not looking for. lol SAS = Serial Attached SCSI. nice features are: Dual ported drives: Makes it easy to connect a drive to redundant controllers Bus expanders: Essentially switches for drives. Connect a bus expander to a SAS port and then connect drives or more bus expanders to the ports of the bus expander. Way more than 7 or 15 drives per connector that way. Two bus expanders connected to the dual ports of a pile of drives and to two controllers could make a rather robust setup with many drives. I believe the number of drives within a single domain is in the thousands. Might have a throughput problem though if you have too many drives going into a single controller port, but then again, sometimes throughput isn't what is required. SATA drive support: A single SATA drive can be connected to any SAS controller port. Can not be connected through bus expander though. SATA to SAS converters are however likely to exist to assign an id to an SATA drive so it can be connected to a bus expander. SATA drives do not get dual ports though, so no increased reliability with SATA drives. Initial speed is 3Gb/s (same as SATA version 2). Later 6 and 12 are going to be released. Of course like SATA the connector is designed for hotplug operation. There are also external connector versions of the port, unlike SATA. I expect prices to be just as scary as for parallel scsi. Devices are expected to ship this year. http://www.serialattachedscsi.com/ Len Sorensen -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
