Which Raid 0 system?

Discussion in 'Mac Pro' started by afavreau, Dec 6, 2010.

  1. afavreau macrumors newbie

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    #1
    Hi,

    I'm about to switch from a MacBook Pro to a Mac Pro (2006). On this Mac Pro, I would like to have a Raid 0 system (2 drives) for my sound library, so I'm wondering what is the best way to do this.

    Since I already have a raid 0 system in an external enclosure that I connect through a SATA Express card, one easy way to do this would be to just buy a SATA card for the Mac Pro, but is this the best way because I know that Apple sells a Mac Pro Raid Card. Is that really better or just the same as my external SATA system?
    Why is that card so expensive?

    And if I should just buy a SATA card for my Mac Pro, which one should I buy?

    Thanks for your help

    Andre Favreau
     
  2. firestarter macrumors 603

    firestarter

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    #2
    Raid 0 as in:
    - Same latency as a regular disk
    - Double the throughput of a regular disk
    - More than double the probability of data loss compared to a regular disk

    What sort of sounds are you accessing to need these features?
     
  3. afavreau thread starter macrumors newbie

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    #3
    I use it for my plug-ins for Logic Pro. They are huge soundbanks for drums, basses, piano (Ivory) ... I don't mind loosing them because I could just re-install.

    What do you mean by:

    - Same latency as a regular disk
    You mean the time it takes to respond or react when asked for?

    - Double the throughput of a regular disk
    You mean the amount of data it can process per second?

    Thanks
     
  4. firestarter, Dec 6, 2010
    Last edited: Dec 6, 2010

    firestarter macrumors 603

    firestarter

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    #4
    Latency is the time you have to wait before you start accessing data (the time it takes for the disk heads to move to the right position).

    Throughput is the amount of data per second you can read off the disk.

    Raid 0 is the 'striping' of data. Alternate pages are held on each disk... so the latency is the same as a regular disk since you have to wait for both disk heads to be in the right place, but the throughput is up to double - since you're reading off both disks in parallel.

    Sound libraries are big, but the individual samples aren't that large. I would have thought that your main concern would be to reduce latency, not to increase throughput - so a Raid 0 may not be the right choice for you.

    A great choice would be SSD - since there's no physical disk head to get in to the right place the latency is tiny. Throughput is good too.

    Also look at Western digital velociraptor disks. They use a small disk (laptop size) spun quickly, so both latency and throughput are improved compared to regular disks.

    Finally, you may be best off just increasing main memory. Apps like Kontakt try to load stuff into memory anyway - much faster than accessing off disk.

    Edit:
    Seriously - I just read that you were upgrading from a laptop.

    Get a 600GB Velociraptor and plenty of main memory. The difference in speed compared to your current setup will blow you away.
     
  5. afavreau thread starter macrumors newbie

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    #5
    You are right that it would be good to evaluate if I really need a Raid 0 first.

    I use

    Synthogy Ivory and the Italian Expansion. In their manual they recommend using Raid 0, so that's why I went with that type of system a couple of years ago. I will probably upgrade to their new version soon.

    Spectrasonics Trlilian, Omnisphere and Stylus.

    Toontrack Superior Drummer 2.0 with New York Expansion

    Also, on my MacBook Pro 2.5 Ghz (2008), I as satisfied with the latency. I could bring the buffer size in Logic down to 64 and piano and drums without noticing the latency, so I presume that the Mac Pro (Woodcrest 2.6ghz) would be fine in this regard too.

    Thanks, I appreciate your help
     
  6. firestarter macrumors 603

    firestarter

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    #6
    Are you hosting in Logic or ProTools?

    And are you running your DAW in 32bit or 64 bit mode?

    You might find that with more memory and 64bit mode, the DAW can keep more of the sample library in memory, so you don't have any stuttering or problems playing samples in realtime.

    How big are your sample libraries in total? 160GB solid state drives are quite well priced these days and that would be so much faster than a Raid 0 of regular disks.

    Personally, I'd get the computer, upgrade the main memory (don't buy memory from Apple - it's too expensive) and install either a Velociraptor or an SSD - then see how things are.
     
  7. afavreau thread starter macrumors newbie

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    #7
    I'm hosting in Logic 9.

    I want to switch to 64 bit and this is the whole reason I want to change to a Mac Pro. The problem I have right now in my laptop is the RAM limit. At 32 bit and 4 GB max, it's not enough. CPU and disk speed seem fine.

    On my Raid 0 drives, I think I'm above 200 GB and the new Ivory will add more.

    Thanks
     
  8. firestarter macrumors 603

    firestarter

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    #8
    How are you connecting your Raid 0 drives at present? Using firewire 800? One cable to both drives?

    Bear in mind that a fast internal disk on a Mac Pro will be double the throughput of a single Firewire 800 connection. You'll see a big speed increase just getting off a laptop.

    I think with the internal disk bus speed, in combination with the increased memory and 64bit mode you should be able to run this stuff without messing with Raid 0.
     
  9. afavreau thread starter macrumors newbie

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    #9
  10. Transporteur macrumors 68030

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    #10
    Why so negative towards RAID0?

    I've been using striped arrays in my workstations for more than a decade now and never experienced any pitfalls. n-times the sustained performance of a single drive certainly never is a disadvantage and personally, I think the higher fault rate doesn't really cut it for a two drive array.

    At any rate, a decent backup system should be in place, no matter if you run a single drive or a striped array. Sure, the possibility of failure is 100% higher for a two drive array, but does it really matter? Replace the faulty drive, play in your backup and you're good to go. Doesn't differ from the procedure of restoring a single drive.

    Disc failure is inevitable, but that alone shouldn't prevent users from striping drives.
     
  11. afavreau thread starter macrumors newbie

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    #11
    Personnally, I don't rermember having any problem with data loss on my 2 Raid 0 Drives.

    However, I had a lot of problems with it's enclosure. The Power Supplies, I just found out, were never too good. I also had to be carefull and treat them right in the procedure.
     
  12. philipma1957 macrumors 603

    philipma1957

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    #12
    look at the classifieds on this site. there are listings that can be of help to you.
     
  13. firestarter macrumors 603

    firestarter

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    #13
    I'm not. I just think there's often a geeky zeal for RAID systems on technology forums that isn't matched by their real life benefits. So it's worthwhile questioning what the aim is before recommending them.

    Certainly there's a lot of misunderstanding about RAID 5 - and many people who assume it's equivalent to having a backup.

    It sounds like the OP has been successfully running RAID 0 on the MBP and could have the same success on the MP. On the other hand, 64 bit logic, more system memory and a faster drive might mean that RAID isn't required - and that will save both cost and risk.
     
  14. afavreau thread starter macrumors newbie

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    #14
    So, before I buy a RAID card, I will try to just put my drives in the Mac Pro and see how it goes.

    However, I still have a few questions. Since I allready have an external SATA dual enclosure with 2 drives, it may still be a good idea to use it.

    1-So I'm wondering, of these two, which system should be quicker?
    a) A single drive IN the Mac Pro?
    b) 2 external Drives in Raid 0 connected to a SATA card to the Mac Pro?

    2-Also, if I would decide to use my external Raid system, which SATA card should I go for? Granite Digital sells one at 50$, Sonnet has one (4 ports) at 300$!!!

    3-Lastly, I see that Apple has a Raid card for internal drives. How does that work? Can it be used for just 2 drives only? Is that much faster than using an external SATA enclosure?

    Thanks
     
  15. nanofrog macrumors G4

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    #15
    There is no need to run a RAID card to stripe a pair of disks (the ICH can even handle a pair of SSD's in a stripe set), as it's a minimal load on the system.

    Just slap a pair if disks in the HDD bays, and create a stripe set under Disk Utility. It's easier, cleaner, and cheaper (generally speaking, based on the need to buy enclosures and cables).

    No money in it but the disks in this case, and the system will be capable of handling it just fine. :)

    It uses the HDD bays (connects via PCB traces on the backplane board - one with the PCIe slots and HDD connectors soldered to it).

    But it's a pile of junk, so stay away. You can do better, and for less money if you really need a RAID card. But from what you've posted so far, you don't need it at all.
     
  16. afavreau thread starter macrumors newbie

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    #16
    What???

    Are you saying you don't need a Mac Pro Raid card to create a Raid 0 system inside your Mac?

    Then what is the Raid card for?
     
  17. philipma1957 macrumors 603

    philipma1957

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    #17
    First off forget the apple raid card. It is for suckers.


    Lets say you really need a raid card and silly fast speed. you buy an external 8 bay box add 8 hdds a good high end raid card and you are off to the races. good raid cards serve speed size safety. you do not need all of that.

    your mac pro has 4 easy to use internal hdd bays use 1 for the boot drive. use 2 for a raid0 use the 4 fourth for a time machine. then use your external as a cloning backup. use superduper or ccc.


    you can use a ssd as your boot drive.
    a pair of wd raptors as your raid0
    a 2tb wd as your time machine and what ever as your external cloner.


    look at the forums market place people have some items you can use. or buy new from newegg owc etc.
     
  18. nanofrog macrumors G4

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    #18
    Correct.

    Disk Utility is capable of running levels 0/1/10 without any additional hardware. You can even use simple SATA/eSATA cards or other non-RAID Host Bus Adapters (example) to increase the port count (add drives), and it will work with those as well.

    Now there are some limits to more than just the levels.
    1. There are only 6x built-in SATA ports (aka ICH for future reference - I and others use this acronym often)
    2. The ICH has a bandwidth limitation of ~660MB/s or so, which is why you can't use but 2 fast SSD's without throttling (what happens when the set is capable of delivering more throughput than the ICH can actually handle).
    3. Nor do SSD's scale as you'd expect on the ICH (mechanical disks fare well in this case, as they're much slower per disk)
    4. Disk Utility is a software implementation for RAID, so it uses system resources (stripe sets, RAID 0, won't consume that much, but you need to be aware that you are using system compute cycles - there is no free lunch, but it's cheap enough in this case that it usually won't matter - it is higher with SSD's than mechanicals due to the shorter completion time between each read or write)

    Beyond what software implementations can offer, is primarily redundancy (levels software RAID cannot or should not be used for), additional capacity and throughputs (more ports = more disks), and recovery options.

    What this means, is if you wanted to run a parity based array (5/6 or nested parity 50/60), you must run a card in the MP (there are software products that claim they can do RAID 5, but software RAID cannot handle the write hole issue associated with parity based arrays). That issue is only solved via hardware (NVRAM), which you get on a proper RAID card.

    Additional ports can allow for more members to be added to a set. This means the raw capacity is increased (usable capacity is dependent on the level used), and the throughputs increase as you add drives as well (parallel operation of disks is where the speed increases come from, and are also dependent on the level used).

    Cards offer additional recovery options and features not found in software implementations, particularly Online Expansion (allows you to add members without data loss). It also makes it easy to transfer the array from one system to another (hardware is transferable, and so long as you don't need to change anything, the array and more importantly it's data, remain in tact). You can't do that too often with software implementations.
     
  19. afavreau thread starter macrumors newbie

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    #19
    Wow! Thanks for your answer.

    So ok, bottom line, how would you guys configure my HDs in my MP?

    At the moment, for my MP, I have:
    -One system drive at 7200 rpm (250GB)
    -One 7200 rpm drive (500GB) for for my audio recordings. It is 200GB full. (Very important data)
    -One 7200 rpm drive (500GB) for the Clone of my Audio and System drive.
    -Two 7200 rpm drive (2 X 250GB) as Raid 0 for sound library. It is 250GB full and most likely to expand. I have these sounds on DVDs so loosing them wouldn't result in a loss, only a lot of re-installation. I also add a second backup of my Audio drive (so that's 450GB total)
    -I don't have any Time Machine backup.

    -One FW800 enclosure
    -One dual SATA enclosure, but no SATA card to hook it up to the MP.

    Starting my applications fast is not very important for me. What is important is that when I run Logic 9, I want to be able to play, open and record many plugins and audio files. I also want to have low audio latency, meaning, when I play a plugin or play a mix, I want it to respond quickly. The Plugins I have (Ivory, Trilian, Omnisphere, SD 2.0...) also need to process large data.

    Also, realistically, I'm not gonna throw away what I have and buy 5-6 SSD or Raptors immediately. However, it would be nice to know the ideal so I can gradually improve in the right direction.

    Thanks for your help
     
  20. nanofrog macrumors G4

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    #20
    You will really want an SSD for your OS/applications and sound libraries (only need one, but make sure it's of sufficient capacity), as a mechanical stripe set won't make much of an impact for loading such files (depends on random access, which mechanical's don't do very fast, striped or not). This configuration is good for large files, as that would be sequential access, which mechanical stripe sets are good for.

    Place the SSD in the empty optical bay so you can boot it (you'll need a SATA cable, and a Molex to SATA power cable). One of the HDD bays can be used as well, but it will mean an adapter. You can use Zip Ties or Velcro in the empty optical bay, though there are mounts available if you prefer.

    • 500GB disk for completed audio projects
    • 500GB as backup
    • 250GB as a clone (external FW800 would be a good place for this)
    • 2x 250GB's for whatever you want to use them for (eSATA enclosure)
    Example for an eSATA card (won't boot).

    I was hoping to get you to consider a RAID 10, but you need 4x disks, and the capacity will be based off of the smallest disk (you'd only get a usable capacity of 500GB from what you have on hand), but it will be faster for sequential access and redundant as well. And you'd be left without a clone or backup, so that's not really an option ATM. Not without buying more disk/s to serve as a backup at a bare minimum (clone is a wonderful thing to have, so you'd really want to get 2x disks if you decide to consider this).

    As per SSD's in RAID, you'd need a 6.0Gb/s compliant hardware RAID card, SSD's, and mounting/enclosures to place them in. Which all translates to a substantial bit of cash (over $1k without blinking).
     
  21. firestarter macrumors 603

    firestarter

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    #21
    As nanofrog says (and I said earlier), SSD is a worthwhile choice for your OS and sound libraries, as it gives you the reduction in latency that a mechanical hard drive (even RAID 0) will not.

    The Western Digital Velociraptor 600 drives are very good - and if you can afford to use them throughout then I'm sure you'll like them. In theory they might be more noisy that regular drives, but I'm using one as a boot disk and I haven't noticed that.

    I'd encourage you to use larger disks for this build rather than smaller disks. If you compare a modern 1TB disk to your current 250GB disks, the data is packed a lot more densely on the higher capacity drive. For a single revolution of the disk, more data is read off the platter - so the data rate is so much greater. In short - these modern 1TB to 2.5TB disks will feel a lot faster than your current smaller drives.

    In addition, since a track on the outside edge of a disk is longer than at the inside of a disk, more data can be stored on it - and more data is therefore read off the outside tracks than the inside tracks (per revolution). If you buy (say) a 2TB Western Digital Barracuda, and create a 250GB partition at the start of it (which is the outside of the disk), then you'll find that you get extremely high data rates and also low latency (the disk head doesn't have to skip backwards and forwards so much, as you're just using the outside tracks). Smart choice of drives and partitioning can increase speed quite a lot.
     
  22. afavreau thread starter macrumors newbie

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    #22
    Yes! I can see how raptors and SSD are the way to go, especially SSD.

    If I'm a typical home studio, musicians are probably among artists the next one in line to greatly benefit from SSD with needs of about 400GB per volume and a ever ending need for speed and responsivness.
     

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