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New SATA vs SCSI
Which is "better" and why? SCSI costs $1/gb while SATA costs $.50/gb (ebay prices). Performance issues? Reliability?
A good friend will come and bail you out of jail ... but, a true friend will be sitting next to you saying, "Damn...that was fun!"
New Re: SATA vs SCSI
I don't know if ATA has caught up yet, but SCSI has always been able to do multiple reads and writes to the drive... which is good if you're doing a lot of reading and writing to the drive.

Also, for a long time studios that did digital recording preferred using SCSI drives because there was less of a chance that there would be digital skipping on those drives.

Perhaps ATA caught up? All I've seen is that those drives get bigger and faster... but I haven't heard anything about multiple writes.
"We are all born originals -- why is it so many of us die copies?"
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New Google "Tagged Command Queue"


Peter
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New Google SATA-II
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[link|http://it.slashdot.org/comments.pl?sid=134485&cid=11233230|"Microsoft Security" is an even better oxymoron than "Military Intelligence"]
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New I'm not looking for specs
But personal experiences from those who have used both. I have used SCSI for years. I know nothing about SATA drives. Before I make an upgrade decision, I'd like to find out what the collective WE knows.

Thanks,

Joe
A good friend will come and bail you out of jail ... but, a true friend will be sitting next to you saying, "Damn...that was fun!"
New IIRC that's IGM, btw, OK?
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New Thank you. I knew we had a TLA for it. couldn't thunk it.
A good friend will come and bail you out of jail ... but, a true friend will be sitting next to you saying, "Damn...that was fun!"
New SATA is nice.
The cables are very thin and easy to connect, unlike the wide IDE ribbons and fingerbusting HD power cables. You don't have the cable length issues that old SCSI drives had, and the termination issues are taken care of too.

SATA CD-ROM drives can be problematic because not all SATA controllers support ATAPI over SATA. That is, your SATA controller will probably work fine with a SATA hard drive, but may not work with a new Plextor CD-RW SATA drive. See, e.g., [link|http://z.iwethey.org/forums/render/content/show?contentid=182506|#182506].

I don't know if SATA does the magical scatter-gather type stuff that SCSI's done for years or not. Some googling would answer that.

I'm a big fan of SCSI, but it's hard for me to justify the expense these days. I've become a fan of RAID mirrors and lots of hard drive space. The biggest SCSI drive I have is a 36 GB Ultra2 drive on a TekRAM controller; my biggest SATA drive is 160 GBx2 RAID mirror. It's easy to see what I've bought more recently.

There may be some OS considerations as well. If you want to do SATA RAID you might have some issues with Linux using the common motherboard controllers.

I would use the money you've budgeted for SCSI for a RAID mirror and/or more RAM and/or an external FireWire or USB2 HD rack or something like that instead. Unless, of course, you need 15k RPM drives or the like.

My $0.02.

Cheers,
Scott.
New Here ya go
I've used SCSI and Fibre Channel drives for years.
I've wasted a few moments here and there with IDE.

SATA is NOT IDE. Combine SATA drives with a decent
3Ware controller and they will outperform almost
anything.

Their native streaming read rate is about 20% faster
than FC, while their seek time is a bit less, which
a good caching controller will "wash" out.

My Bonnie++ tests showed my dual opteron with
6 SATA disks and a 3ware controller outperforming
every other system in my computer room, including
some 3 year old high-end FC gear.

When I then tested against my brand-new EMC CX700
with stacks of 140GB FC drives, I found that the
3ware SATA controller was a bit slower for writes,
a LOT faster for reads, and a bit slower for seeks.

But this merely meant it wrote a measly 300MB (that's
megaBYTES per second) while reading at around 170MB
per second. As compared to the EMC writing 380MB
per second and reading 100MB per second.

I started running multiple tests at the same time,
and found the degradation to be very graceful.

I will very happily use SATA for the majority of
my work in the future. The only reason I don't
have it now was the EMC CX700 using FC disks was
cheaper than the IBM using SATA, plus more heads
is better for seeking. Also, I got 2 CX700s, which
meant 4 times the FC <-> switch connections. If
I bought the IBM it would be a single system with a
measly 4 wires coming out.

Right now my home PC uses 250GB SATA disks. I NEVER
feel like I'm waiting on IO.
New Thanks Barry, Just what I was looking for.
A good friend will come and bail you out of jail ... but, a true friend will be sitting next to you saying, "Damn...that was fun!"
New According to the drive/controller industry . .
SATA is the low end and SATA clusters will be branches on SSCSI (Serial SCSI) trees for handling the less demanding jobs. Serial SCSI is a whole new world of storage, but SATA is here now and performs about as well as old parallel SCSI. SSCSI is still in the late stages of development but is planned to be the core of future multi-terabyte storage systems.
[link|http://www.aaxnet.com|AAx]
New SSCSI is really...
A rewrite of a combo of SSA timing and Dual Ringing, with (U320-style) SCSI Byte-endcoding.

If anyone has really used SSA here, then they know exactly why this is significant. Redundant paths to the device, with async and sync access to any SSA device, at the same time.

That said, real SATA-II devices (not SATA devices with SATA-II enhancement in front of the real chipset on the drive) will really show what SATA can really bring to the table.

Another point is, since the encodings are amazingly similar, in ideas and execution, I wonder if there will be a point, when to get either, depends on the controller you buy, making only one "style of drive" with 2 ports for access on it.
  • Single ended controller for consumer machines, giving the transfer speed, but reduced performance because of no second channel
  • Single ended dual channel controller for entry-level servers and High-End consumer machines, giving enhanced multi channel performance and redundancy in access, but no failover ability
  • Ring based controller with a single ring, for Entry-Midsized servers, giving very good speed and possibility of benefit of a ring config and the benefits of multiple paths of access
  • Ring based controller with Dual rings, benefits from redundancy of access through 2 rings, and the performance that then garners.
  • Ring based mirroring controllers, any design... and it just continues.

--
[link|mailto:greg@gregfolkert.net|greg],
[link|http://www.iwethey.org/ed_curry|REMEMBER ED CURRY!] @ iwethey

[link|http://it.slashdot.org/comments.pl?sid=134485&cid=11233230|"Microsoft Security" is an even better oxymoron than "Military Intelligence"]
No matter how much Microsoft supporters whine about how Linux and other operating systems have just as many bugs as their operating systems do, the bottom line is that the serious, gut-wrenching problems happen on Windows, not on Linux, not on Mac OS. -- [link|http://www.eweek.com/article2/0,1759,1622086,00.asp|source]
     SATA vs SCSI - (jbrabeck) - (11)
         Re: SATA vs SCSI - (cwbrenn) - (2)
             Google "Tagged Command Queue" -NT - (pwhysall)
             Google SATA-II -NT - (folkert)
         I'm not looking for specs - (jbrabeck) - (5)
             IIRC that's IGM, btw, OK? -NT - (drewk) - (1)
                 Thank you. I knew we had a TLA for it. couldn't thunk it. -NT - (jbrabeck)
             SATA is nice. - (Another Scott)
             Here ya go - (broomberg) - (1)
                 Thanks Barry, Just what I was looking for. -NT - (jbrabeck)
         According to the drive/controller industry . . - (Andrew Grygus) - (1)
             SSCSI is really... - (folkert)

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122 ms