Striping 4 SSD's?

Discussion in 'Mac Pro' started by dsa420, Sep 8, 2009.

  1. dsa420 macrumors 6502

    Feb 23, 2007
    Presently I have (1) 128GB SSD as the boot drive for my Mac Pro and the performance has been pretty impressive. Would I see substantial performance differences by striping 4 SSD's together to run as the boot drive?

    Thinking I would ditch the 128GB drive and pick up (4) 64GB or 32GB SSD's. Would then use the "hidden" 2 SATA ports on the mother board to stripe (2) 1TB drives for storage.
  2. oculus42 macrumors 6502

    Dec 9, 2002
    You would need a RAID card to handle striping your boot volume. SSD striping performance seems to peak (per dollar) at three drives. The fourth drive gets you performance, but not the linear increases from two or three drives.
  3. jdl8422 macrumors 6502


    Jul 5, 2006
    little off topic, but where are you mounting your two 1tb drives? Are you mounting them in the optical bay?

    Also, what kind of work do u do on your MP that needs the performance of an SSD. I'm not judging, just curious. I don't doubt the speed increase, im just curious what would be the reason for spending the money on an SSD, unless you just have money laying around lol. Thanks
  4. ungraphic macrumors 6502a


    Nov 15, 2007
    Toronto, Canada
    No you dont, OS X has software raid. I've got my boot volume striped without a raid card.
  5. oculus42 macrumors 6502

    Dec 9, 2002
    My error, though software striping of your boot volume sounds less than optimum.
  6. TheStrudel macrumors 65816


    Jan 5, 2008
    Or more to the point, a four-disk SSD stripe sounds like the point where you're waiting on the RAM or CPU. Heck, you'd probably be doing that with three or two sufficiently fast SSDs.
  7. dsa420 thread starter macrumors 6502

    Feb 23, 2007
    none of the work that i do "requires" such speed, i just have a bunch of drives that i could sell on ebay to fund this deal to pay for the SSD's. would love to see speeds matched of my MBP that has (2) SSD's striped presently.

    it seems my Mac Pro drags in comparison to my MBP.
  8. TheStrudel macrumors 65816


    Jan 5, 2008
    Which SSDs? And you must be selling quite the haul...

    I've toyed with the idea of 2 X-25Ms or OCZ Vertex drives striped, but I'll be doing a lot of saving for time to come, first.
  9. jdl8422 macrumors 6502


    Jul 5, 2006

    Wasn't judging, just curious. What drives are you selling?
  10. alphaod macrumors Core


    Feb 9, 2008
    If you're going to stripe 4 SSDs, I would get a dedicated RAID card because the limit on the built-in RAID is about 1000MB/s,
  11. nanofrog macrumors G4

    May 6, 2008
    It's less than that. Those using stripped SSD's on the ICH10R are only getting 650 - 660MB/s out of it.

    So anything more than that, a hardware controller of some sort is needed. As it happens, to boot from it, it will end up being a RAID controller (proper, NOT Fake RAID), as those are capable of booting into the EFI based firmware on the MP's (some of the Areca's btw). The least expensive would be the ARC-1210.
  12. Tesselator macrumors 601


    Jan 9, 2008
    I don't understand how this can be true. I can get 1,200 MB/s out of a 3-Drive RAID0. I thought the limit was something like 360 MB/s per drive. There are 6 drive ports so that should be a little over 2 GB/s. And then there's a bus limit that's something like 2 GB/s. I've even read Nanofrog confirm these in the past. So what's changed?

    Here's a small sample of me getting WAY over 600 MB/s:

             I/O Transactions
      Frame     MB/sec
               Read      Write      
    00.0      611.3      404.2      
    01.0      841.6      917.0      
    02.0      859.3      930.9      
    03.0      835.9      813.8      
    04.0      718.6      923.9      
    05.0      830.3      896.9      
    06.0      859.3      890.4      
    07.0      853.3      718.6      
    08.0      758.5      660.6      
    09.0      847.4      740.2      
    10.0      847.4      841.6      
    11.0      787.7      917.0      
    12.0      819.2      917.0      
    13.0      438.9      903.5      
    14.0      803.1      903.5      
    15.0      938.0      890.4      
    16.0      847.4      884.0      
    17.0      871.5      556.0      
    18.0      865.4      896.9      
    19.0      859.3      859.3      
    20.0      835.9      896.9      
    21.0      819.2      859.3      
    22.0      853.3      884.0      
    23.0      853.3      824.7      
    24.0      830.3      706.2      
    25.0      835.9      587.9      
    26.0      671.5      853.3      
    27.0      923.9      871.5      
    28.0      983.0      853.3      
    29.0      671.5      865.4      
    30.0      871.5      859.3      
    31.0      787.7      877.7      
    32.0      813.8      853.3      
    33.0      871.5      859.3      
    34.0      975.2      650.2      
    35.0      917.0      803.1      
    36.0      991.0      824.7      
    37.0      877.7      853.3      
    38.0      1015.5      727.1      
    39.0      945.2      813.8      
    40.0      1024.0      803.1      
    41.0      967.6      782.7      
    42.0      1077.9      671.5      
    43.0      1077.9      841.6      
    44.0      1077.9      853.3      
    And here's another 3-Drive RAID0 on the same machine using the 2 ODD ports and one fitted connector (slider):

             I/O Transactions
      Frame     MB/sec
               Read      Write      
    00.0      731.4      359.3      
    01.0      1228.8      653.6      
    02.0      1241.2      556.0      
    03.0      1228.8      808.4      
    04.0      1041.4      841.6      
    05.0      1241.2      749.3      
    06.0      1293.5      727.1      
    07.0      1241.2      835.9      
    08.0      1253.9      803.1      
    09.0      1041.4      731.4      
    10.0      1241.2      706.2      
    11.0      1253.9      626.9      
    12.0      1266.8      813.8      
    13.0      1241.2      841.6      
    14.0      1041.4      485.7      
    15.0      1253.9      722.8      
    16.0      1253.9      702.2      
    17.0      1253.9      694.2      
    18.0      1253.9      772.8      
    19.0      853.3      590.8      
    20.0      819.2      808.4      
    21.0      1032.6      787.7      
    22.0      952.6      835.9      
    23.0      1015.5      803.1      
    24.0      859.3      819.2      
    25.0      1068.5      787.7      
    26.0      1159.2      614.4      
    27.0      753.9      650.2      
    28.0      1148.4      636.7      
    29.0      1137.8      753.9      
    30.0      1127.3      847.4      
    31.0      830.3      710.3      
    32.0      917.0      710.3      
    33.0      952.6      722.8      
  13. nanofrog macrumors G4

    May 6, 2008
    Hey Tess, I'd checked into the ICH10R, which does seem to have this limitation. As your system doesn't use it, you're in the clear.

    SATA has a limit of 375MB/s for each port (3Gb/8)*1/s. And the overall bandwidth would be enough to handle this (DMI from previous architecture, and certainly QPI). But I think they set a fixed limit on the X58 chipsets, as it has to share that bandwidth with other devices. They may have done this to keep one area from taking total control under high load situations. Not absolutely sure, and still want to spend more time on the datasheet to see what I can find out.

    But the evidence is out there on the ICH10R's embedded in the X58/5520 chipsets.

    In my case, the drives are attached via a RAID card, so the data is routed through the PCIe interface, completely skipping the chipset's SATA ports.
  14. kdeda macrumors newbie

    Sep 9, 2009
    I am sure this has been discussed in length some other part.
    But which RAID card ?

    I am having a hard time finding one that allows booting.
    Without too much tweaking.
  15. Tesselator macrumors 601


    Jan 9, 2008
    So this is another case of me not knowing what we're talking about. :p I see. But wait. dsa420 doesn't say which Mac Pro he has - so no one knows what we're talking about... Right, or am I still getting it wrong?

    Which Macs or Mac Pros have the X58/5520 chipsets?

    According to this the 2006/07 Mac Pro is 5000X, the 08 Macs are 5400, and the 2009 Macs are Intel X58. So only the 2009 Mac Pro suck? Man! More bad news about machine and spec crippling in the 2009 models. Good thing Apple doesn't practice honesty in advertising - they wouldn't sell a single 2009 Mac Pro. This is sad!

    But only for the 2006 through 2008 Macs and the 2009s are much less? Or am I still misunderstanding?
  16. nanofrog macrumors G4

    May 6, 2008
    Without specifics (port count,...), it's hard to give you a specific model, but check out Areca and Atto Technolgies.

    Both make cards that will boot OS X (EFI boot support). Not all of the Areca's do, so pay close attention to the specs. All of the SAS models do, but a couple of the SATA models do as well IIRC (i.e. ARC-1210 & ARC-1220). Please note, that SAS models are extremely picky with SATA drives. If you want to use them, pay close attention to the Hardware Compatibility List. Areca has validated some SSD's (Intels for sure, but check for the specific model. IIRC, it's Gen1, 80GB -M & -E models).

    It's enough to get you started I think. ;)

    If you offer up some details, members can offer more help. Perhaps sending PM's or start a new thread.
  17. nanofrog macrumors G4

    May 6, 2008
    It's limited to the Nehalem parts. So it only affects the '09 MP's, and PC's using i7/Xeon 35xx/55xx parts. Lots of information in board makers forums. I spent most of the time in ASUS's, as that's who makes my board. :D

    Presumbably, it would also affect the i5 parts becomming available as well, and the i9's/Gulftown Xeon's when they ship (IIRC, they'll use the same chipset).

    375MB/s is the technical limit, but I'd imagine you're seeing some overhead losses (latency). So 360MB/s per port is nothing to complain about. :D :p
  18. gugucom macrumors 68020


    May 21, 2009
    Munich, Germany
    I'm using the Areca 1210 which is not exactly cheap but seems to be a well made kit in comparison to Highpoint stuff and what Apple floggs as RAID cards.

    Once you get over the initial hurdles of figuring out the cryptic documentation and getting the web interface to pop up it works nicely in a Mac. The modular BIOS accepts a Mac pluggin and from there it is easy sailing. I havn't used it for RAID yet because my Intel 80GB Postvilles are stiil en route. But nanofrog seems very confident it will do that nicely as well.

    My only issue at this time is a noisy fan that isn't really needed in the Mac Pro with it's elaborated cooling system. Unfortunately the Taiwanese have not thought of designing a software method to switch off the fan monitor in a Mac Pro. So the little bugger keeps giving me warnings until I will fit it in a Windows box to switch the fan monitor off.
  19. aibo macrumors 6502

    Jan 17, 2008
    Southern California
    I'd advise against striping 4 SSDs in RAID because the speed would make your head explode.
  20. Tesselator macrumors 601


    Jan 9, 2008
    OK, I understand. Wow, it really sucks to be a 2009 Mac Pro owner - on SO MANY levels!. :(

    I was actually getting a little over that and closer to 375 MB/s so it's just me making a mistake in thinking it was 360 when it's actually 375. Now let's see if I can remember it right the next time this comes up 4 or 5 months from now. :D
  21. TheStrudel macrumors 65816


    Jan 5, 2008
    Yeah... I hope the 2010 Mac Pro has more design advances than design/price flaws.
  22. nanofrog macrumors G4

    May 6, 2008
    Their products are a significant improvement over anything I've ever seen from Highpoint. :)

    If you think the manual's bad, try emailing them. :eek: :p

    I dont' see why it wouldn't work, as they've passed Intel SSD's (both M & E models IIRC) on the ARC-1231ML and the ARC-1680 series. They all use the same basic firmware and electronic components. Systems engineering done well. ;)

    The fan may have been added as they were expecting it to be installed in rackmount cases. For a larger case, I don't think it's anywere near as critical. Even some models with larger port counts don't have them, but the connector is there so it can be added as an option. I did on the ARC-1231ML, and though it was running at 50C, the fan dropped it 10C. Useful, but it's not a stock fan. I used a 40mm Addonics I found on eBay.

    Nah. MORE speed! :D


    A RAID card can solve it (ICH10R on the 5520 chipset), buy why should a user be forced into using one with SSD or even fast mechanical SATA due to poor design? That's a really raw deal. :(

    At least you're getting near, if not the absolute limit. :D

    A far sight better than the ICH10R on the X58/5520 chipsets at any rate. :p

    My concern is the design flaws will not only follow, but so will the pricing, and maybe even made worse. :(

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