Mac Pro with 2 raid setups?

Discussion in 'Mac Pro' started by Chad H, May 23, 2009.

  1. Chad H macrumors 6502a

    Chad H

    Joined:
    Feb 13, 2008
    Location:
    Auburn, AL
    #1
    Hey guys,
    I have been thinking about redoing my HD setup in my new mac pro. I have been reading up on Raid 0 setups(mirrored/striped) and was wondering if not only did I have the "concept" correct but would this setup offer anything significant?

    I currently have all 4 HD bays full with the main drive being on a WD 1.5TB HD and the others being WD 1TB drives. On the 3 1TB drives I store all my media/music and other misc. On the 1.5TB HD is where OSX and my Windows 7 Partition reside. The idea I had was to get 2 WD Raptor drives(300GB each) and install those in slot 1 and 2 and have those drives setup in a Raid array. I would also install 2 2TB WD drives in bays 3 and 4 and install those in a Raid array also.

    Now, would this benefit me? If I am understanding RAID correctly that would be 640GB for my main drive and 4TB on my media drives if I did a striped setup. I'm just wondering if it would be beneficial and would the read/write times be that much faster?

    I mainly do ripping/encoding(DVD's), hard gaming(windows), and some light photography work. Any help would be great and if it is going to be beneficial what Raid setup would you suggest and which cards? My setup is below.

    Mac Pro 2.66(in signature)
    8GB Ram
    ATI Radeon
     
  2. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #2
    A stripe of 2 Velociraptors would give you a speed boost for the OS X/apps useage. It would be a problem for Win7 though, as the stripe is created under OS X. Win7 can't read the stripe. Not because of the file format, but because the stripe was set up under OS X.

    If you want to boot the RAID into a multiple OS environment, you would need to select a RAID card that supports a multiple OS boot capability. This is both tricky (details in the specs), and expensive. It would likely be a SAS card, and would require enterprise drives to stick with SATA. (SAS is really picky about SATA drives). It would go over $600USD just for the card. Then add in the drives, which cost more than their consumer counterparts, and possibly some cables at ~$30 each (each handles 4 HDD's).

    As per the 2 2TB stripe, it would be slower. First, the lower number of drives. Second, those are Green Power models, and are more akin to a 5400rpm disk (they vary the spindle speeds, but is usually run at 5400). Individually, they're capable of ~77.7MB/s Avg. Throughput (STR), so would would only produce ~150MB/s in a 2 drive stripe.

    Overall, you'd get better speeds by placing all the drives in a single stripe for OS X, and use a separate single drive for Win7.

    Hope this helps. :)
     
  3. Chad H thread starter macrumors 6502a

    Chad H

    Joined:
    Feb 13, 2008
    Location:
    Auburn, AL
    #3
    Okay, so what about this. What if I bought 2 raptor drives. One for Mac OSX and the other just for Windows 7. With the last two bays is their a way to stripe those with something that would increase read/write times for media(encoding/ripping) or decrease the time it take for my itunes library to load(its huge).
     
  4. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #4
    Use one Velociraptor for both OS's using partitions (Bootcamp for Win7), provided you're installs can fit.

    Then stripe 3 drives for the iTunes library. You could also use the stripe for applications as well, if you wish. This would cut down on the capacity usage on the VR, and give a speed boost as well.

    You also want to make sure you have a backup in place, as a stripe has no redundancy. If anything goes wrong, the entire array is shot, as a file is stored in peices on ALL drives in the set. An external drive(s) is an easy solution, and not too expensive either.

    BTW, do you have an empty optical bay available?
     
  5. Chad H thread starter macrumors 6502a

    Chad H

    Joined:
    Feb 13, 2008
    Location:
    Auburn, AL
    #5
    No I decided to get 2 super drives. What drives do you recommend for the 3 drive raid? Also can you suggest a good card?
     
  6. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #6
    As far as HDD's, I lean towards WD these days. Take a look at the RE3 series. But if they're being used with a RAID controller, you need to check the HDD Compatibility List published by the card's manufacturer. They test out drives to determine which will or will not work properly. Doing this first can save you all kinds of headaches. ;)

    As for cards, take a look at:

    Both of these are capable of booting OS X. It requires a firmware change (EFI version) on the highpoint. There's an EFI version available for Areca's products as well. Win7 (and Vista) claim to support EFI firmware, so it shouldn't be a problem, assuming it works as advertised.

    The best thing to do, is send email to their respective companies, giving an explaination of what you want to do. Just to make sure. Otherwise, you'd end up requiring a separate boot drive for Windows. Not that big a deal, but still. (I usually take the safe approach, and use a separate drive for the secondary OS).

    As per the second optical drive, it's possible to remove it, and place it in an external enclosure. they aren't that expensive either, particularly off eBay. Perhaps not as attractive, but far less expensive to do this to accomodate an internal RAID configuration, vs. going external with it.

    This seems to be a sticking point for some, but compromises seem to be required to squeeze in an internal RAID configuration consisting of more than 4 drives.
     
  7. Tesselator macrumors 601

    Tesselator

    Joined:
    Jan 9, 2008
    Location:
    Japan
    #7
    Also if you plan to use BootCamp to set up the windows drive or partition you have boot from a single drive. I've noticed that when booting from a RAID none of the Bootcamp tools and facilitates work. I can't comprehend how this would affect booting multiple OS's on a single RAID and I dunno how to set up the windoze side by hand without bootcamp.
     
  8. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #8
    Bootcamp isn't needed if Windows goes on a separate drive, and seems to be a fairly simple way to avoid the hassle. :D

    This is what I'd do anyway. Boot off the separate disk, then use drivers to access the array. The time saved by booting off the array is countered by the card's boot time (initialization), even to the degree it takes longer. :eek: ;) Partitioning it out for a Win and OS X sections is the difficult part, and it's not too much hassle. :p

    5 disks, one OS can boot off the card, and both OS's can access an array(s), and the least aggravation. :D Woot. :p
     
  9. Chad H thread starter macrumors 6502a

    Chad H

    Joined:
    Feb 13, 2008
    Location:
    Auburn, AL
    #9
    Well what if I ran 2 raptors in bay 1 and 2. Those will be Mac OSX and Windows 7. Then I can fill the last 2 bays up with 2 2TB drives. But their arent any speedy 2TB drives out yet are they?
     
  10. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #10
    Running the VR's as single disks for each OS would work fine. :)

    But for 2TB drives, NO, there's not any fast models available yet. The WD's version is a Green Power, and isn't that fast, given some throughput data I've seen (STR = 77.7MB/s for a single drive). :( Not terrible, but... ;)

    You'd have to wait, or go with smaller drives. 1TB capacity drives would be the best bet for speed IMO. For now. But you've given me the impression you want more capacity, and I presume budget constraints would prevent you from going with 1TB models now, only to upgrade in 6 months or so when the fast 2TB models might show. (I wouldn't either). ;) :D

    This is where it can get difficult in a Mac. You'd need additional space ATM, and the optical bay method is the only solution for an internal system. Otherwise, you'd need to go external using an eSATA card for communication, and the necessary enclosure(s).

    Either is possible, but requires more effort, and slightly more $$$. Particularly due to the fact your second optical bay is occupied (a single 5.25" enclosure for that to get the internal space). But IIRC, you can do that for ~$40USD. Possibly less on eBay.
     
  11. Chad H thread starter macrumors 6502a

    Chad H

    Joined:
    Feb 13, 2008
    Location:
    Auburn, AL
    #11
    Well, budget isnt that big of a deal. I think my main problem honestly is my main drive being the 1.5TB WD green version. Thats what is bottlenecking my entire system.
     
  12. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #12
    If budget isn't an issue, you'd very likely prefer to use SSD for the OS drives. But I do tend to think in terms of value, and SSD will depend on specifics.

    It can compare well to a 3 drive RAID 0 in terms of STR, but will beat the crap out of it for Random Access. This is what OS and app usage really needs, and why those that have them are so impressed. :D Specifics matter, and I would urge you to examine your usage carefully before making any purchase.

    If your useage will perform a lot of writes, SSD's not the way to go, given the UBE of a cell is much lower than a mechanical drive. 1E4 or 1E5 vs. 1E14 or 1E15 on mechanical, despite the wear leveling and TRIM implementations used with SSD. These techniques just can't produce that much of an increase to UBE. I've not seen the proof anyway, despite the articles published by Anandtech or Tom's Hardware. They didn't actually cover this issue head-on IMO.

    If you will primarily only read the data, you'd be fine. And given the space constraints, it makes more sense. Fewer drives get you major performance.

    You could create a balance as well, and given your descriptions, seems ideal. Run the OS's off SSD, and write the data to the array (mechanical drives). You get the advantages/benefits of both. HDD bottlenecks will be solved as best as they can be, given the available internal space.

    Beyond that, you're going to need to go with an external solution, and it has a habit of not being cheap. :p
     

Share This Page