The Push For SCSI (or at least Serial ATA)

Discussion in 'Macintosh Computers' started by rice_web, Oct 29, 2002.

  1. macrumors 6502a

    rice_web

    Joined:
    Oct 25, 2001
    Location:
    Minot, North Dakota
    #1
    The ONE gripe that I have with "modern" computing concerns hard drive speed. One of the few reasons that applications load slower from one machine to the next is almost entirely due to hard drive speed. So.....

    GIVE US SCSI OR GIVE US DEATH (or at least Serial ATA)

    SCSI - 15,000 RPMs, BABY
    These hard drives are wickedly fast. Seagate has been making 15,000 RPM hard drives for a while now, and have reduced seek times to 3.6ms, and increased transfer rates to roughly 70MBps--nearly as fast as the memory found in the iBook.

    Yeah, they're LOUD, but so are the fans in the PowerMac; the difference in noise level would be slight, if any.

    Serial ATA
    This is a technology that has me excited, even though I know very little about it.

    Serial ATA II is due late 2004, but offers transfer rates more than double the current parallel ATA-133 (at least theoretically)

    A Dumb Conclusion
    If the Mac world really wants something to be proud of, imagine a page file of roughly 10GB that is nearly as fast as the system memory, thus negating the need for 1GB of RAM (which wouldn't hurt).

    Yes, processor speeds still need to increase dramatically. Until that happens, Apple should be doing its part to increase performance wherever and whenever possible.
     
  2. Lz0
    macrumors regular

    Joined:
    Jul 20, 2002
    Location:
    Melbourne
    #2
    Tell me, what's the price on one of these 15000 RPM HDD???
     
  3. thread starter macrumors 6502a

    rice_web

    Joined:
    Oct 25, 2001
    Location:
    Minot, North Dakota
    #3
    Roughly $900 for a 73GB hard drive.... :D

    Seriously, though, a 15000RPM hard drive at 36GB would only be $300-$400.
     
  4. macrumors 6502

    Joined:
    Oct 28, 2002
    #4
    Drives

    I use a 5200 (or is it 5400) 60 GB drive and have no trouble at all collecting live DV straight to my drive. I've seen a post like this here before I'm sure. I think the main conclusion was SPECIFICATIONS. Apple loves em, and so do I.

    Conclusion
    Bring on those SCUMMY drives if they meet the SPECIFICATIONS. But if I'm not mistaken, ATA is our friend for many reasons that Apple has taken to heart.:D
     
  5. macrumors 601

    Chaszmyr

    Joined:
    Aug 9, 2002
    #5
    I have a 20gb 15000 rpm SCSI drive from Seagate in my computer... let me tell you, its not that much faster. Unless youre using SCSI RAID you might as well go with IDE RAID over SCSI because its cheaper and faster.
     
  6. macrumors 68030

    Catfish_Man

    Joined:
    Sep 13, 2001
    Location:
    Portland, OR
    #6
    Ahg!!!!...

    ...<brandishes rod of techno-death, smites Parallel IDE/ATA and SCSI>. SerialATA, please. For one thing, 15,000rpm SCSI drives are NOISY, for another, they're EXPENSIVE, for another, they're SMALL (in storage space, not physical space). Plus, you've got all the crappy termination issues to deal with, and it's not hot swappable like SerialATA.

    Also, if the iBook's memory transfered just over 70MBps, Apple would be long dead. It transfers 800MBps.

    SerialATA is hot swappable, small (ever seen how big an Ultra160 SCSI connector is? Mobo space costs money), backwards compatible (driver-wise) with parallel ATA, and has massive industry support. SerialATA has 150MBps max transfer speeds, SerialATAII will have 300MBps, SerialATAIII will have 600MBps. It has most of the advantages of SCSI, without most of the problems. Also, SerialATA kills the annoying Master/Slave issues that current ATA has (with the penalty that it only supports one drive per port, which is not much of a penalty as the small size allows for more of them on one mobo).

    Bring on the SerialATA Macs!
     
  7. macrumors member

    g4pismo

    Joined:
    Jul 17, 2002
    Location:
    Atlanta
    #7
    My 10k 36g IBM drives can heat my office..My vote is for S-ATA.
     
  8. macrumors demi-god

    szark

    Joined:
    May 14, 2002
    Location:
    Arid-Zone-A
    #8
    SAS!!!

    I'm holding out for Serial Attached SCSI !!! ;)


    (By the way, SCSI drives are hot-swappable when using SCA connections)
     
  9. macrumors 604

    MacBandit

    Joined:
    Aug 9, 2002
    Location:
    Springfield, OR (Home of the Simpsons)
    #9
    The IBM 80Gig 7200Rpm drive that came in my new dual has an average transfer rate of 40MB/s. Combine two of these stripe them and you should be able to get somewhere around 75MB/s average. All this speed for less then $300 and you would have a total capacity of 160gigs.

    Sorry but SCSI is all but dead with the price and speeds of the modern ATA drives.
     
  10. macrumors 65816

    Nipsy

    Joined:
    Jan 19, 2002
    #10
    As a longtime SCSI holdout, the price performance ratio finally caused me to switch.

    I have a 480GB RAID in my machine for $750, which gives me 90MB/s sustained read, and 75MB/s sustained write (4 x IBM 120GXP and a SIIG 133 RAID card).

    For about the same price, I could have acheived these speeds with SCSI (2 Cheetahs and a Dual channel U160) card, and had a whopping 36GB to work with.

    I still dislike some of the IDE penalties as far as read/write delays, but for anyone who's bothered, SCSI is always a BTO option.

    Neither SCSI nor IDE are going to break 50mb/s (sustained) in single drive configurations anway.

    It is impossible to justify the costs for consumers, business users, and anyone not dealing with db/video/48 track audio, etc.

    IDE is about $1/GB, and SCSI is $10...people already complain that Macs are too expensive.

    Notes:

    SCSI Drives are always hot-swappable (provided they are in an appropriate carriage).

    A dual IDE RAID on one channel will likely give 130-140% performance, because IDE does not process commands in parallel.

    A dual SCSI RAID on one channel will usually give 160-170% performance, as SCSI accepts concurrent instructions.

    New Seagate Cheetahs 15Ks do run quiet, and cool, but are still very expensive.

    Memory round trips are measured in nanoseconds (~10), SCSI seeks start at 3MS, plus the round trip to the drive, so paging to a drive is still 30 times slower than visiting RAM.
     
  11. macrumors 604

    MacBandit

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    Location:
    Springfield, OR (Home of the Simpsons)
    #11
    Real knowledge is such a great thing. Thanks for the post.
     
  12. macrumors newbie

    Joined:
    Oct 29, 2002
    #12
    every single message on this thread is horribly incorrect

    Nipsy gets the award for having only one flaw
     
  13. macrumors 65816

    Nipsy

    Joined:
    Jan 19, 2002
    #13
    That being?
     
  14. macrumors 604

    MacBandit

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    Location:
    Springfield, OR (Home of the Simpsons)
    #14
    Damn Trolls anyhow. They reach up at you from under the bridge and growl but they don't tell you what about. Explain yourself when you make a post don't just say you were wrong.

    After reading Nipsy's post I too realize I had a mistake in my thread. I overated the total possible throughput of a ATA Raid. If you are counting though that is also the only mistake in my post.
     
  15. macrumors newbie

    Joined:
    Oct 29, 2002
    #15
    rice-web: ibook does not go @ 70MB/s, Serial ATA will be released @ 150MB/s, but will not offer increased transfer rates

    BenderBot1138: I have no idea what 'specifications' are, Apple uses ATA because it's cheap (no other reason).

    Chaszmyr: Yes, it is much faster, you just don't notice it because your computing patterns most likely follow a brief burst of loading and then a long period of interacting with cached data. Additionally, IDE Raid does not help latency and will require over two disks to match a SCSI if both are operating sequentially and at max speed

    Catfish Man: SCSI is hot swappable, SCSI is compatible between U2, 160, and 320; that's more than can be said for Parallel -> Serial ATA. Additionally, any OS will have built in drivers for SCSI adaptors. Furthermore, you're just talking about bus speeds, which is pointless. Serial ATA does not have massive industry support, not compared to SCSI and non-serial ATA.

    MacBandit: Your IDE hard drive will not get an average of 40 MB/s, even if reading sequentially. SCSI is not dead unless you're cheap and don't care about your data/uptime. Although you might be talking about yourself, if you say that SCSI is dead, you have to face the fact that you are not the world, and SCSI is in no danger from SATA.

    Nipsy: SCSI will break 50 MB/sustained, although your math for the RAID array seems right.
     
  16. macrumors 65816

    Nipsy

    Joined:
    Jan 19, 2002
    #16
    Agreed, in a RAID config, my old SCSI RAID sat happily at ~215MB/s (PCI Bus saturation) sustained both ways (ATTO Dual U160, 8 Cheetahs).

    However, when used as individual drives (which 95% of people are running) did not break 50MB/s sustained either way. The drives were Dec. 2001 Cheetah 18GB drives, and would happily peak at about 45MB/s read, and 40MB/s write (sustained) on the ATTO card.

    My point is that people who want Serial ATA or SCSI, and only use one drive don't understand that they won't see a benefit.

    A 45MB/s drive will give 45MB/s on a LVD, U160, U320, ATA66, ATA100, ATA133, or serial ATA bus. However, as you add (up to 15) drives to SCSI, you can saturate the SCSI, and even the PCI bus. When you add a drive to ATA, you are unlikely to staurate the bus (ATA133 or PCI) as you can only have 2 ATA drives per channel, and the drives themselves aren't fast enough.

    In the future, as drives read more info faster, they will nip at the heels of busses, and busses will grow faster as well, but if you use one drive on a bus, you are msiing the point of faster busses.
     
  17. macrumors 6502

    avkills

    Joined:
    Jun 14, 2002
    #17
    This is funny...

    I do not care how you slice it, SCSI whips ATA like nobody's business.

    Anyone who needs ultra fast storage has always and will always use SCSI RAID arrays, either using Ultra160, Ultra320 or FibreChannel.

    That being said, 90% of most users can happily compute using cheap-o ATA drives. Hell, even I have a 80gb Firewire drive for video for use with my iBook, but if you expect to me to admit it is even close in speed to my 2 Ultra160 drives in my tower, then I also have part of the brooklyn bridge to sell you.

    -mark
     
  18. macrumors 68000

    tjwett

    Joined:
    May 6, 2002
    Location:
    Brooklyn, NYC
    #18
    I've used 15,000 RPM fast SCSI drives as well as 10, 000 and they do indeed make a difference with video and audio. Personally I don't think 7200 is enough for these uses unless the drive is very carefully formatted and optimised. SCSI is a must. No shizzle.
     
  19. macrumors 604

    MacBandit

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    Aug 9, 2002
    Location:
    Springfield, OR (Home of the Simpsons)
    #19

    How can you tell me the hard drive in my computer is not able to achieve 40MB/s? Have you been secretly sneeking into my computer room at night and rerunning all the test that I have done that show a read throughput of 40MB/s and a write throuput of 36MB/s?
     
  20. macrumors 604

    MacBandit

    Joined:
    Aug 9, 2002
    Location:
    Springfield, OR (Home of the Simpsons)
    #20
    I am in no way saying that an ATA drive will ever compare to a SCSI drive in speed. What I am saying is that it is cheaper to buy two huge ATA drives and use them in a array and end up with a setup that is not only cheaper then the 15,000Rpm SCSI but is also faster (read and writer through not access) and has lot more storage room.


    I say SCSI is dead because in a sense it already is. The average consumer no longer uses SCSI in there computers it has been pushed into the high end market only. SCSI will end up if it isn't already just like Beta. Even though it is the better idea it just doesn't make in the main stream.
     
  21. macrumors 6502

    Joined:
    Oct 30, 2002
    Location:
    Austin, TX
    #21
    And unfortunately, other technologies are pushing down in the high end (large servers). Its been a while since we spec'd SCSI in anything other than an internal development server for example, and for those ATA would be fine if it was available (we're mainly an AIX shop). The reality is that SCSI now has an incredibly small "sweet spot" ... small enough to reduce future R&D efforts and keep prices high, which further reduces the sweet spot, etc, etc.

    It was indeed a great technology, but one whose time has almost certainly passed.
     
  22. macrumors newbie

    Joined:
    Oct 29, 2002
    #22
    Just last week an associate, who runs a private server in his closet (who is certainly a mainstream consumer) had to replace his Quantum fireball after only 1 year of service. He ran it 24/7 in a hot server closet, and it started dying (sectors going bad, I think). He's now using SCSI. And btw, if you somehow think that servers only using SCSI is some great HD conspiracy created to justify $700 HD's that only hold 36GB, think again. IDE hard drives are built to fail after far less use, have worse latency/seek time penalties, have an inefficient bus...They lose on every category but cost and storage size. I have no idea what you base your strange ideas of IDE Raid beating out SCSI on, but it's not happening in the professional sector. I went to dell and looked at the PowerEdge servers...the only server I found that used IDE was a $1300 entry level. All the rest used SCSI. I have no idea why you think that SCSI is dying, please tell me.


    The reason of course that I'm claiming that your harddrive isn't averaging 40 MB/s is that only one IDE HD gets that, and I'm betting you don't have it. I don't know how you benchmark it, (maybe you're looking at cached data? maybe you're just looking at the outer zone?)
     
  23. macrumors regular

    Joined:
    May 4, 2002
    #23
    i have an IDE RAID 0 setup on my pc, and it's definitely fast enough to notice a difference. apple needs to get a heads-up on some of these cool new technologies. except IDE RAID is like 2-3 years old now.
     
  24. macrumors 604

    MacBandit

    Joined:
    Aug 9, 2002
    Location:
    Springfield, OR (Home of the Simpsons)
    #24
    I've never once said that an IDE raid setup could replace SCSI in a professional system. It would work just fine in a home semi/pro office though at lower cost and bigger size. If you read the whole thread you will see that I and others have explained my stance on SCSI death. Maybe death is too harsh a word how about it's fall out of mainstream. It has gone the way of Beta as I have said before. It is being used primarily for professional only use. That being servers and high end graphics/audio systems. That market is very small in comparison to the mainstream average computer user and that is what I base my argument on.
     
  25. macrumors regular

    Joined:
    Jul 8, 2002
    #25
    Actually, my 120GB Western Digital special edition nudges up really close to 50MB/s sustained, the Seagate X15-36LP (15k rpm) is up around 65MB/s

    (your point mostly stands, but your numbers were outdated :))
     

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