SAS vs. SCSI

[TeeJayHoward]

With the advent of products like THIS, I'm wondering just how long "traditional" (ribbon-cable) SCSI's going to hang around.

Anyone have a speed comparison between the U320 and the SAS versions of this drive? Are there any advantages to the U320 over the SAS? (I know the SAS supports SATA also, and tons of drives and port multipliers and whatnot.)

I mean, it's only a $40 difference...

In short... Oh noes! Is SCSI obsolete?

 

[draksia]

I can tell the performance difference between SAS and parallel scsi is less then the marginal of error in the testing.

We I see SAS taking off pretty quick there are still huge amounts of investment in parallel scsi enclosures, HBA's and raid controllers that most people don't just want to throw away. If look SATA it has been around for quite a while and there are still many ide drives out there. I can't think of any new hard drives that are not available in both IDE and SATA. I think SCSI will stick around even more longer because it has a much more expensive invested base then IDE has.

 

[feigned]

Is SCSI obsolete?

Not by a long shot.

Eventually yes, but not yet. I can't wait...the clusterfuck in our db box is nuts because of the three SCSI cables going to each of the HBAs...the door is a bitch to get shut.

 

[USMC2Hard4U]

I dont think SCSI is obsolete. I would still take a USCSI 320 Raid array over my SATA drives

 

[UICompE02]

Parallel SCSI will be around for a long, long time. There's an incredibly huge installed base that still must be supported and U320 controllers and drives probably haven't hit the peak of their sales yet (very soon, though!)

U320 really doesn't have many advantages over SAS. Maybe that you can connect 15 devices to a single cable, whereas SAS requires a separate cable for each device and needs an expander for hooking up more devices than you have ports.

However, SAS cables are much cheaper than U320 SCSI cables (you can use SATA cables if you want) and there are no termination headaches that plague parallel SCSI. Plus with a shared parallel bus, you're much more likely to run into compatibility issues between target devices than you are with each device on its own bus.

 

[feigned]

U320 really doesn't have many advantages over SAS. Maybe that you can connect 15 devices to a single cable, whereas SAS requires a separate cable for each device and needs an expander for hooking up more devices than you have ports.

So the whole port multiplier stuff isn't a shared bus with SAS?

However, SAS cables are much cheaper than U320 SCSI cables (you can use SATA cables if you want) and there are no termination headaches that plague parallel SCSI. Plus with a shared parallel bus, you're much more likely to run into compatibility issues between target devices than you are with each device on its own bus.

No termination is good, seperate bus is even better.

So no more fanagling with SCSI IDs and other various horse puckey.

 

[UICompE02]

So the whole port multiplier stuff isn't a shared bus with SAS?

Yes, you have a good point there. But one thing you can do is route up to four ports to the expander and have a 12 gbits/second pipe to whatever drives you have attached. Also they aren't shared in the sense that parallel SCSI is since each device is not talking physically to the same bus, but to a switch in the expander.

No termination is good, seperate bus is even better.

So no more fanagling with SCSI IDs and other various horse puckey.

Exactly. It's way easier to set up a SAS system than a parallel SCSI system. It truly is plug and play now as each SAS device has it's own factory-assigned WWID (worldwide ID) that the controller uses to talk to it.

 

[tdg]

In short... Oh noes! Is SCSI obsolete?

No, because SAS is SCSI

And I dont see parallel SCSI going away anytime soon, this is similiar to the PATA to SATA transition. We've had SATA controllers and drives for years now, but PATA is still build and sold, and even after they are officially obsolete, there will be a lot of people still running the parallel versions of IDE and SCSI for quite some time.