Raid 0 Macbook Pro

Discussion in 'MacBook Pro' started by Macsavvytech, Apr 6, 2011.

  1. Macsavvytech macrumors 6502a

    Macsavvytech

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    #1
    Hi there!
    My 2011 MBP is on order after a store broke my 2010 MBP, anyway i plan on buying a 128GB vertex 3 and putting it into RAID0 with the existing Apple SSD.
    I have Two questions:
    1) I understand the risks of RAID 0 i.e. one drive dies, all your data is gone. however is there any other reasons not to do this?
    2) I will install windows 7 bootcamp and i would prefer to keep the drives in RAID0 for the performance boost however is that a bad idea? Should i instead put windows on one drive mac on the other.

    Additional Details:
    - All my data will be regularly backed up to a external hard drive (time machine)
    - My partition setup will be (i think) Mac OSX 140GB Windows 100GB ( i understand this will differ slightly over provisioning)
     
  2. mediasorcerer macrumors regular

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    #2
    excellent question mate,im intending on doing the same thing,have a look at the front page on the "maxupgrades site,top of page,and you will get an idea of how fast the performance will be with raid o enabled between two ssd,s[check out with two vertex -3,s!!!]its over 500 mb/ps!!!,madness,

    i always thought it was just a matter of data loss frankly,if u are going the internal optical bay route,then it can be read as one volume or you can install bcamp on one /osx the other,but remember cant install win from external drive i believe,so has to be done with drive in mac apparently,owc has tutorials on how to do it i believe,it will make for killer machine,i dont know that much about it,but the atapi /dvd super drive port maxes out at 3 gb/ps not 6gp/ps,some thing to consider,thats the best way to do it i think,unless thunderbolt=10 gb/ps theoretical,or usb-480?gbps?,so internal atapi[dvd etc] port is the go i think!!!???

    id like to know more too,thinking same way.good one;)
     
  3. Macsavvytech, Apr 6, 2011
    Last edited: Apr 6, 2011

    Macsavvytech thread starter macrumors 6502a

    Macsavvytech

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    #3
    My current SSD is one of the apple SSDs that doesn't even breach sata 2. I figure I should get 680MB/s, current SSD (~180MB/s) + Vertex 3 (~510MB/s)
    EDIT: Just to clarify my old SSD will go in a optibay.
     
  4. Transporteur macrumors 68030

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    #4
    Doesn't work like that. The smallest and slowest drive in the setup determines the speed, so you'd end up with ~500MB/s sequential read speeds in total (uncompressed data).

    The single Vertex will be faster. But keep in mind, OS/apps doesn't benefit from high sequential speeds. It's the random 4K speeds that accelerate the OS/apps and those speeds don't scale properly with a RAID setup.
    So by all means, leave the Vertex by itself and don't include the stock Apple drive in this setup!
     
  5. Macsavvytech thread starter macrumors 6502a

    Macsavvytech

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    #5
    Doesn't RAID 0 treat both hard drives as one and copy to both of them simulatanously therefore combining their speeds, gives the total speed? Or is that a different RAID?
     
  6. Transporteur macrumors 68030

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    #6
    That's right, but keep in mind that a RAID 0 stripes the data equally to both hard drives. So the faster drive would have to wait for the slower drive to complete the write/read process before being able to access other data again.

    Makes sense?
     
  7. johnnj macrumors 6502a

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    #7
    Windows isn't going to see the OSX RAID volume that you would have set up and you won't be able to install it to a separate partition within the volume as you would have if it was just a normal single drive. One reason being that this is only software RAID.

    However, you can still enjoy the benefits of striping under OSX while having a Bootcamp install of Windows. If you want to still do that with the lopsided configuration you're proposing is up to you.

    I wrote a short procedure on doing this two years ago. That and the follow up questions on the thread should make it easy for you to do.

    http://forums.macrumors.com/showthread.php?t=676856&highlight=

    Good luck and remember... when it comes to performance, money is no object!

    John
     
  8. Macsavvytech thread starter macrumors 6502a

    Macsavvytech

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    #8
    So basically someone needs to make RAID 0 more efficient ;(

    Anyway more seriously, is this also correct. Example
    You have a 300MB/s drive and a 100MB/s drive, the bandwidth on this setup in raid would be 200MB/s.
    You have a 2x200MB/s drives, the bandwidth on this would be 400MB/s.

    Are both these statement true? Is my reasoning finally correct?
     
  9. Macsavvytech thread starter macrumors 6502a

    Macsavvytech

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    #9
    Can I infer from this that software raid is different to hardware raid.
    I am guessing software RAID is limited by slowest drive whereas hardware is as I sated earlier combined. I am also guessing that hardware RAID requires a RAID card.
     
  10. johnnj macrumors 6502a

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    #10
    Right. A card. Most performance oriented PC mobos have an integrated RAID controller, too. It's sort of like, but not exactly like comparing the integrated video controller that shares system RAM to the dedicated video controller that we all have in our laptops.

    No. Hardware RAID controllers won't magically make slower member drives as fast as the fastest member. I've actually never even considered making a RAID volume of any sort without all the drives being the same, so good luck if you're trying that. If you want to do it for maximum effect, get a pair of drives of a speed and capacity you'll be satisfied with and just go from there.
     
  11. Macsavvytech thread starter macrumors 6502a

    Macsavvytech

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    #11
    What performance are you getting on your RAID setup. 2x256GB SSDs. I'm envious!
     
  12. johnnj macrumors 6502a

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    #12
    http://forums.macrumors.com/showthread.php?t=1131855&highlight=

    The last benchmark I ran last night got me over 400 MB/sec on both max read and write. The machine is noticeably faster than it was with the old pair of Vertex 1 120 drives.

    I did notice one issue this morning, though. I have a Windows Home Server and I have three SMB mounts in my logon items. The network interface (ethernet) isn't up before the OS tries to mount the first share and it fails. The other two mount fine and when I go back and do the 1st one manually it's fine.

    John
     
  13. Transporteur macrumors 68030

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    #13
    No. The first one would result in a 100MB/s throughput (slowest drive).
    The second one is right, though. You won't reach exactly twice the performance, but it's very close.

    As already mentioned, hardware RAID doesn't affect your examples at all. The results would still be 100MB/s and 400MB/s.

    Hardware RAID controllers can only be found on very few workstation grade (or server) boards. The usual desktop grade boards come with a fake RAID controller (software based).
     
  14. johnnj macrumors 6502a

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    #14
    You're right. The Intel Storage Matrix thing is a firmware RAID system, at least according to the Wikipedia article. It runs on the motherboard itself but still isn't dedicated hardware. I stand corrected.
     
  15. johnnyturbouk macrumors 68000

    johnnyturbouk

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    #15
    i always had the impression that RAID0 was best achieved using identical drives.

    I am also interested to see if one drive is negotiated with sata 3 and the other sata-2 how this will pan out with the overall performance and reliability?

    i plan on getting x2 ocz vertex 3 240gb - but was led by believe by ocz tech support and others on the ocz forums that this set-up would not really work as only one drive is linked to sata 6 - so i would get sub-standard speeds

    i could buy a vertex 3 and a vertex 2 for the optibay which would achieve a similar result as x2 v3s - altho i am under the impression that 4k and sequential writes are hella lot faster on the v3 on a sata 2 port.

    :confused::confused:
     
  16. johnnj macrumors 6502a

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    I can't speak to the reliability yet, but the performance is pretty good. No signs of instability so far. Booting is consistently fast and the system seems stable. Large file transfers have been no problem and my Parallels XP vm boots faster than I've ever seen one boot.
     
  17. johnnyturbouk macrumors 68000

    johnnyturbouk

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    #17
    im so tempted ... two crucial c300s -256gb in raid0
    or a v3 + v2 240gb

    the crucial seem really tempting now with the trim hack and the fact that they are so cheap
     
  18. maflynn Moderator

    maflynn

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    #18
    Data security is not a reason enough?
    I don't think using apple's RAID implementation is compatible with bootcamp. That is you'll not be able to boot up windows 7 from bootcamp with that. I could be wrong, as I've not done this. I recall seeing some discussion on this over at the apple.discussions.com but this was years ago.
     
  19. johnnj macrumors 6502a

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    #19
    Maybe for someone without a rigorous backup strategy.

    Answered both above and 2 years ago:

    http://forums.macrumors.com/showthread.php?t=676856&highlight=
     
  20. paulrbeers macrumors 68040

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    #20
    What? If one drive is 300MB/s and one drive is 100MB/s, then they would have a total of 200MB/s. Basically the RAID will be waiting on the second drive thus making the first drive to do no better than 100MB/s, so it's like having 2 - 100MB/s = 200MB/s in RAID 0.

    Frankly though, other than sequential read/writes, RAID 0 is not that much faster in real world experience.
     
  21. Transporteur macrumors 68030

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    #21
    Whoops, I got confused with the numbers. You're totally right of course.

    As I said earlier, the slowest drive determines the speed of the array (n times the sequential speed of the slowest drive with n being the amount of drives).
    The same applies for capacity.

    You're right about the sequential speeds as well. Random speeds is what makes the OS/apps fast, not sequential speeds. Unfortunately random speeds don't scale well with software RAID controllers. I've seen as little speed increases as 10%, on the other hand drastic decreases as well. It's just not worth it.
    Just a quick real world example, opening Photoshop CS5 makes a 1 second peak of 44MB/s on my Intel SSD. It won't open any faster with a 500MB/s sequential speed array. ;)

    The only viable option for an OS/app RAID0 from SSD drives I see is capacity, since smaller drives tend to be cheaper ($/GB) as larger ones. Performance wise, it doesn't make any sense at all.

    There are other applications for a SSD RAID0, such as scratch discs that actually benefit from higher sequential speeds.
     
  22. Macsavvytech thread starter macrumors 6502a

    Macsavvytech

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    #22
    Hehe I was right. Anyway I'm thinking of doing this. Vertex 3 for Mac, Apple SSD for windows, Dell Ultrasharp 23" as second monitor and my existing R.A.T. 7 mouse on my goliathus mouse mat XXL. Now I just have to wait another 2weeks for my computer. Oh and if my budget allows Lacie LittleBig Disk, SSD Thunderbolt.
     
  23. DaveOZ macrumors regular

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    #23
    I had Raid 0 setup on my MPPro 17" with 2 x OCZ Vertex 256 GB SSD last year. It worked perfectly and I have a 2 Tb backup disk that gets plugged in every day. After a few months I wanted more space so I went back to 256 SSD boot drive and 750Gb drive in the Optibay.

    Not sure I would want mixed drives in a Raid 0 setup though.
     
  24. Macsavvytech thread starter macrumors 6502a

    Macsavvytech

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    #24
    Oh and to this, I always store my most important stuff on my
    USB, FireWire hard drive and wuala. My machine also time machine backup itself. So loosing one hard drive and my
    Data going would only be annoying because I would have to get the drive fixed
     
  25. DarwinOSX macrumors 65816

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    #25
    A single Sata 6 drive is the same speed as two Sata 3 Raid O drives. Thats the route I would consider.
     

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