Serial ata vs. scsi

Posted:
in Current Mac Hardware edited January 2014
Hi



I been thinking ( and that doesn´t happen often!!!8) )



Is it still better to have scsi drives for say video/ audio stuff han ata (serial ata) ? Diffrence in performace ?



What about firewire 800 ?
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Comments

  • Reply 1 of 21
    aquaticaquatic Posts: 5,602member
    Why aren't there NATIVE FireWire hard drives yet? I mean how long is it going to take? FireWire 800 easily matches the throughput of hard drives, even in RAID. So why do we still need bridge chips? Native FireWire drives would make FireWire hard drives in cases much cheaper and the case much smaller. And I assume we wouldn't need a power cable then, the FW could power it. SCSI is dead. Termination issues, short fat unbending cables, and large connectors have always annoyed me. SCSI is, well, scuzzy.
  • Reply 2 of 21
    hmurchisonhmurchison Posts: 12,358member
    Quote:

    Originally posted by maclogic

    Hi



    I been thinking ( and that doesn´t happen often!!!8) )



    Is it still better to have scsi drives for say video/ audio stuff han ata (serial ata) ? Diffrence in performace ?



    What about firewire 800 ?




    Serial is just the Interface. The drives still contain the strengths/weaknesses of the protocol. SCSI still multitasks better than ATA. BTW there is a Serial SCSI coming as well.
  • Reply 3 of 21
    maxcom29maxcom29 Posts: 44member
    Quote:

    Originally posted by Aquatic

    Why aren't there NATIVE FireWire hard drives yet? I mean how long is it going to take? FireWire 800 easily matches the throughput of hard drives, even in RAID. So why do we still need bridge chips? Native FireWire drives would make FireWire hard drives in cases much cheaper and the case much smaller. And I assume we wouldn't need a power cable then, the FW could power it. SCSI is dead. Termination issues, short fat unbending cables, and large connectors have always annoyed me. SCSI is, well, scuzzy.





    SCSI is not dead, at least for servers. There is no reliable standard which allows for internal hotswapping, multiple transfers during a single host-target connection, full RAID (meaning all 5 or so versions) compatibility, and general data protection.

    Additonally, Serial ATA has up to this point not shown itself to be much faster than good ol' IDE, while SCSI easily outperforms IDE drives in apps. such as AutoCAD, Photoshop, and general throughoutput.

    By outperforms, I mean that it is often 20 + percent faster.
  • Reply 4 of 21
    gargoylegargoyle Posts: 660member
    personally i think scsi stands a good chance of fading out. As shown on the serialata.org website, they recon the protocol will be upto 600Mb/sec within 5 - 10 years.



    BUT



    That is not the bottle neck. Current drives still cant sustain even a 100Mb/sec data rate. I think if you get about 48Mb/sec from an ide drive you are doing well. The actual drives themselves will have to evolve in order to take full advantage of these controllers.



    Unless there is some drastic change in the technology, we can only hope that as the current technology refines, we see drives with more spindles/platters and more read/write heads.
  • Reply 5 of 21
    the cool gutthe cool gut Posts: 1,714member
    Quote:

    Originally posted by maxcom29

    SCSISCSI easily outperforms IDE drives in apps. such as AutoCAD, Photoshop, and general throughoutput.

    By outperforms, I mean that it is often 20 + percent faster.




    I have found there to be no measurable performance differences between SCSI and ATA on desktop machines. True you can get 15000 rpm SCSI drives, but their prices just don't make them practical by any means.



    Here are some interesting links regarding the matter:



    http://www.computerworld.com/hardwar...,79768,00.html



    http://www.computerworld.com/hardwar...,79769,00.html
  • Reply 6 of 21
    dsoileaudsoileau Posts: 12member
    Sorry to not have introduced this new topic question as a humorous segue, but I don't have a smiley face icon in profile.



    I'm hoping that I can take a few SCSI drives with me in the G4 to G5 upgrade and that someone can tell me which SCSI controller cards are supported in 10.2, Panther, etc. Cheap would be nice, too. TIA
  • Reply 7 of 21
    eugeneeugene Posts: 8,254member
    Quote:

    Originally posted by maxcom29

    SCSI is not dead, at least for servers. There is no reliable standard which allows for internal hotswapping, multiple transfers during a single host-target connection, full RAID (meaning all 5 or so versions) compatibility, and general data protection.

    Additonally, Serial ATA has up to this point not shown itself to be much faster than good ol' IDE, while SCSI easily outperforms IDE drives in apps. such as AutoCAD, Photoshop, and general throughoutput.

    By outperforms, I mean that it is often 20 + percent faster.




    Both IDE and SCSI HDDs are just as reliable when used with SCA connectors.



    IDE and SCSI both support RAID equally.



    I'm not sure what you mean by 'general data protection.'



    Serial ATA has shown itself to be much faster than good ole IDE when used with the right hardware...as in controllers not hampered by a 133 MBps PCI bus and workstation quality HDDs like the WD Raptor.



    Serial ATA is going to scale up quickly...



    SCSI isn't King of the enterprise world anyway. Fiber-Channel is.
  • Reply 8 of 21
    fluffyfluffy Posts: 361member
    Quote:

    Originally posted by dsoileau

    I'm hoping that I can take a few SCSI drives with me in the G4 to G5 upgrade



    Just to make sure... these are external drives, right? The G5 case design does not allow internal SCSI drives.
  • Reply 9 of 21
    gardnerjgardnerj Posts: 167member
    Quote:

    Originally posted by Eugene

    Both IDE and SCSI HDDs are just as reliable when used with SCA connectors.



    IDE and SCSI both support RAID equally.



    I'm not sure what you mean by 'general data protection.'



    Serial ATA has shown itself to be much faster than good ole IDE when used with the right hardware...as in controllers not hampered by a 133 MBps PCI bus and workstation quality HDDs like the WD Raptor.



    Serial ATA is going to scale up quickly...



    SCSI isn't King of the enterprise world anyway. Fiber-Channel is.




    Walks into computer room ... eyes the racks of scsi disk attached to hp, sun and ibm servers. Nuts... if scsi dead then this must be a morgue.



    Incidentally most fibre channel disk cabs still use scsi disks via a hot swappable back plannar. It aint going anywhere for a long time. The words enterprise standard spring to mind.
  • Reply 10 of 21
    eugeneeugene Posts: 8,254member
    Quote:

    Originally posted by gardnerj

    Walks into computer room ... eyes the racks of scsi disk attached to hp, sun and ibm servers. Nuts... if scsi dead then this must be a morgue.



    Incidentally most fibre channel disk cabs still use scsi disks via a hot swappable back plannar. It aint going anywhere for a long time. The words enterprise standard spring to mind.




    Now don't put words into my mouth...



    I didn't say SCSI was dead, I said Fiber-Channel is king, and it is. And what's with this FC HDDs are actually SCSI based FUD? Is it because there's a 40-pin SCA connector on the back? ... because SCA and SCSI are not synonymous.



    I can go out right now and walk into my old lab's machine closet and look upon a rack full of Sun A1000s. That doesn't mean anything especially considering the direction of maxcom29's argument against Serial-ATA.



    And that doesn't even begin to brush the surface. FC allows for shorter cable lengths, many more attached devices, easier failover. You can create storage networks with a snap of your fingers with FC. Plus having a single type of internal and external connection is most excellent, dude.
  • Reply 11 of 21
    gardnerjgardnerj Posts: 167member
    Quote:

    Originally posted by Eugene

    Now don't put words into my mouth...



    I didn't say SCSI was dead,




    Fair point, i was responding to an earlier post in that respect.



    Quote:



    I said Fiber-Channel is king, and it is. And what's with this FC HDDs are actually SCSI based FUD? Is it because there's a 40-pin SCA connector on the back? ... because SCA and SCSI are not synonymous.





    Fibre channel is faster yes, obviously dependant on how the data is laid out. But also more expensive. Not sure what the connector on the back of each enclosed disk is but inside each hot swap unit is a scsi disk.



    Quote:



    I can go out right now and walk into my old lab's machine closet and look upon a rack full of Sun A1000s. That doesn't mean anything especially considering the direction of maxcom29's argument against Serial-ATA.



    And that doesn't even begin to brush the surface. FC allows for shorter cable lengths, many more attached devices, easier failover. You can create storage networks with a snap of your fingers with FC.




    I thought the issue with scsi was that long cables caused problems. Unless your tying to shoe horn stuff into the back of a cab i don't see where shorter cables would be of use.



    More attached devices true but have you ever tried moving a full populated fibre attach disk rack (say 22-24 disks) between disk cabs it takes several big blokes. And again how many devices do you want on a single channel.



    Either way we're both agreeing that serial ata isn't industry strenght yet.
  • Reply 12 of 21
    gardnerjgardnerj Posts: 167member
    All that said i'm sure IBM was pushing something called ssa technology a while ago, not sure if its still being sold, which was as i recall serial attached.



    Found the link ...



    http://www.storage.ibm.com/disk/7133/index.html
  • Reply 13 of 21
    macubusmacubus Posts: 95member
    fibre channel is just a protocol, it still uses normal (albeit expensive) drives to connect to the switching fabric
  • Reply 14 of 21
    dsoileaudsoileau Posts: 12member
    Does a serial ATA drive, even at 160Mbs, approach the multi function speed of SCSI? Are big serial ATA drives, when adapted to SCSI (bridged), faster and cheaper than SCSI?
  • Reply 15 of 21
    I think the drives themselves limit the future. How reliable are 15,000 rpm drives. And, if you want to go faster, then what 20,000......30,000 rpm.





    I think to really move forward..........we need solid state drives that are big and cheap. There has to be a move of focus to this area. Everything else in computer components are fast outpacing the technology of the Hard Drive.
  • Reply 16 of 21
    Quote:

    Originally posted by aircft.sys.spec.

    I think the drives themselves limit the future. How reliable are 15,000 rpm drives. And, if you want to go faster, then what 20,000......30,000 rpm.





    I think to really move forward..........we need solid state drives that are big and cheap. There has to be a move of focus to this area. Everything else in computer components are fast outpacing the technology of the Hard Drive.




    Remember that as the capacity increases, so does the density of the data, so the data can be read faster. As long as they can continue to fit more space on each platter, I think we could even see lower speed drives become pretty decent again, as a 15,000 RPM drive is not so reliable. Now, in the server front, of course this is not as much of an issue, as each drive has an expected lifespan shorter than a consumer drive. But, as the density becomes greater and greater, I wonder if they would consider making very reliable long lasting drives at slower rotation speeds, and maybe add an extra read/write head....
  • Reply 17 of 21
    gargoylegargoyle Posts: 660member
    how come I make a post, and everyone seems to ignore it. Then at the bottom of the thread someone else comes along and says basically the same thing I did.
  • Reply 18 of 21
    Regarding the initial post, asking about performance differences between SATA and SCSI, I can only talk to the dfferences between regular ATA and SCSI for now, since I've never tried SATA.



    But there is a clear difference when I sequence audio on an ATA drive vs SCSI on the same computer. SCSI is a good bit faster (sorry, don't have benchmarks), and I'm pretty sure it's due to the seek time differences. My Ultra160 SCSI drive seeks in 5.4ms, vs ~11 for my ATA/133 drives. When sequencing lots of audio files (in Logic Audio 6 in this case), seek time becomes very important as you ask the drive to locate and read what can often be many dozes of files, some very small others rather large.



    A 15k RPM SCSI drive has seek times as low as 3.7ms. The fastest SATA drive I've seen is the Western Digital Raptor at 5.2ms. However, when I get my G5 I'm going to put the WD drive in for my audio because the cost of the SCSI drive is just too high.



    The ability of a G5 to hold 8GB of RAM makes drive speed less of an issue since, for audio at least, you can fit all the audio for an average project into RAM.
  • Reply 19 of 21
    aquaticaquatic Posts: 5,602member




    Disclaimer: I've heard Apple's dead too. Numerous times.
  • Reply 20 of 21
    dsoileaudsoileau Posts: 12member
    Quote:

    Originally posted by Fluffy

    Just to make sure... these are external drives, right? The G5 case design does not allow internal SCSI drives.



    No, these are internal drives. Not installable in the G5?! A shortage of bays?
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