Replace drives with SSD or fast HDDs?

Discussion in 'Mac Pro' started by alphaod, Dec 10, 2009.

  1. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #1
    It's the holiday season and I want to upgrade my drives. Currently I'm running 4x 300GB VelociRaptors in RAID 5; they are pretty fast, but they are not fast enough to justify my current lack of space. I'm out of places to put external drives hence the wish to upgrade my internal drives.

    I have looked at a few options including the new 2TB 7200RPM drives that are pretty fast; however I do not need that much space; plus I care more about random access than sequential performance.

    So I have come down to 2 choices. I wish to either get a couple SSDs and put in to a RAID 0 and then back then up very often. Probably 4 Intel X25-M 160GB SSDs if it comes down to that. I know there are faster SSDs out there, but the Intel drives are proven well having bought a couple of their drives and never had any issues.

    The other drive I'm looking at is the 600GB Seagate Cheetah 15k.7; it will double my current capacity, offer substantial speed; the only problem is I don't know how much noise this combination would make. I have no problems running an SAS drive since my RAID controller is built for it. The price per GB on this is slightly over $1/GB which is pretty high, but at least it's fast and will obvious offer about 3.75x more capacity than the Intel SSDs.

    For the time being I'm putting cost aside because I know this upgrade will be very very expensive.
     
  2. VirtualRain macrumors 603

    VirtualRain

    Joined:
    Aug 1, 2008
    Location:
    Vancouver, BC
    #2
    I would definitely go SSD. :D

    But, three SSD's in RAID0 would max out the throughput of the Intel ICH (660MB/s limit), so there's no point in going with four.

    What about a hybrid approach of 2-3 SSD's and one or two large magnetic drives?

    At any rate, the SSD's will shock you with how snappy things will become.
     
  3. Transporteur macrumors 68030

    Joined:
    Nov 30, 2008
    Location:
    UK
    #3
    If you really want to use 4 SSDs (you definitely want to go for the Intel drives, they are the fastest SATA II ones you can get), make sure you buy a decent RAID card to use them with, otherwise, as VirtualRain said before, you get into the controller limit.

    Personally I would not by the expensive SAS drives, they are loud and slower than SSDs.
    For storage I recommend normal magnetic drives in the MacPro sleds.
     
  4. gugucom macrumors 68020

    gugucom

    Joined:
    May 21, 2009
    Location:
    Munich, Germany
    #4
    I support this. In order to max out additional space for 2,5" drives you may want to look at the transintl DX4
    http://www.transintl.com/store/category.cfm?Category=2799
     
  5. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #5
    Even a pair of arrays (2 member set of SSD and 2 member set of mechanical - both in level 0), will hit the limit, but shouldn't throttle.

    Any more than a pair of Intel SSD's will (3*250MB/s = 750MB/s and gets worse as n increases, obviously). If this is desired, the only way to keep the throughput of what the drives can deliver, is to use a separate card (4 port SATA at a min, which can't boot in EFI). If EFI (OS X) booting is desired, the only option is a RAID card that supports EFI boot capability (Areca or Atto Technologies do, as does Apple's POS RAID card).

    Fortunately, alphaod has one. But IIRC, it's Apple's RAID card, which is slow and might not work well with SSD's. I don't recall seeing anything on how well that one works with SSD. A 4x slot should hit the limit with 4x Intel 160GB SSD's (1GB/s read).
     
  6. VirtualRain macrumors 603

    VirtualRain

    Joined:
    Aug 1, 2008
    Location:
    Vancouver, BC
    #6
    Sounds like a good time to benchmark it! :D
     
  7. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #7
    I hope he's willing to guinea pig err... test it for us, as the card is in-hand. :D :p
     
  8. JesterJJZ macrumors 68020

    JesterJJZ

    Joined:
    Jul 21, 2004
    #8
  9. alphaod thread starter macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #9
    Okay guys, nanofrog never remembers, but I have the Areca ARC-1212 card which supports up to 4 drives and 2GB/s of bandwidth. I might upgrade to a ARC-1680xi for 12 drive connectors.

    Yes, if I do get SSDs, I'd need to complement them with a few mechanical drives for space. I'm just going to need to know how to fit all the drives because I'm running the MaxUpgrade sledges to use my third-party RAID card. If I get that TransIntl DX4, how would that integrate with my existing set-up?
     
  10. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #10
    So many different cards in spread out amongst MR users.... :rolleyes: I've not written who has what down anywhere. Some have even switched, making it a bit worse for me. :eek: :p

    The ARC-1212 will fly, and they've tested both the ARC-1231ML and ARC-1680's with Intel SSD's (not sure if it was G2's though), and they passed. So you shouldn't have problems.

    If you're sticking with SATA drives, you could go with an ARC-1231ML, as they've got it working as a bootable device in EFI environments as well (took quite a while, as the card debuted in 2006).

    As per fitting them in the sleds, I'd go with the Icy Dock 2.5" - 3.5" adapter,a s they're cheaper than those by MaxUpgrades (orginally made for the Velociraptors). But if you've already got them, they'll work. No extra $$$ that way.

    For mechanical, how many do you want to run?
     
  11. gugucom macrumors 68020

    gugucom

    Joined:
    May 21, 2009
    Location:
    Munich, Germany
    #11
    It really depends of your MP model and optical bay config. Assuming you have a Nehalem machine you have five ports of which apparently four are running off your RAID card now.

    I don't see much sense in upgrading your Raid card in order to run the SSDs and the HDDs by RAID5. It would only make sense if you need to keep the RAID5 redundancy for all your data. With the decision to use SSDs for system, apps and projects and HDDs for data archiving you should re consider your redundancy needs. You obviously will backup both the archive and the system/apps/project drives. But would it be necessary for business continuity to have the archive data redundant? Probably not because you would not need them for the business day. And if you need them you could get them from the backup.

    This would indicate that redundancy would be needed for your business day data which in future would be located on SSDs. You are considering up to four SSDs so it means you can really still go with your RAID card.

    Considering your archiving needs I would think that 4 TB is likely to give you enough space which then means you can do with just 2 HDD ports that can be directly connected to the Mac Pro original SATA headers. The two other ports could be run with Icy Dock adapters as suggested by nanofrog. The two remaining SSDs can actually go in the 2nd ODD bay with an inexpensive mechanical holder and the two SATA cables from the unused HDD ports would be re routed to the ODD bay.

    If do not want to bother with the ODD bay installation you could still buy a DX4 and sell your 4 sled adapters which you do not need in that case. It would leave you with four ports for archiving and you could use your 1,2 TB raptors for the purpose although it would not really be a sensible use case. Those would probably also better be sold off to make way for a wopping 8 TB archive capacity.

    A final consideration would go to the RAID5 need of your business day data. With SSDs you are more likely to experience a case of data corruption than storage device failure. In such a case the data can usually be restored from backup in an hour. It would make sense to think about dropping the redundancy and just keeping a replacement SSD handy.
     
  12. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #12
    It's an '09.

    I'm assuming he's interested in making an additional mechanical array of 4 drives with extra ports for future online expansion. I'm also thinking the redundancy is needed for work, and level 10 isn't viable (budget/capacity reasons).

    So a larger port count is needed (ARC-1212 = 4 port SAS card) along with an external enclosure + 2x int. to ext. cables (8 drive). Internal could be possible, but 8x won't fit, and a 4 bay unit would be needed anyway + external 5.25" for the optical drive. But the 4 bay unit can be held off until needed (if it's not imediate). The 8 bay enclosure would be cleaner though IMO.
     

Share This Page