Striped SSDs not looking so fly [again]

Discussion in 'Mac Pro' started by alphaod, Sep 30, 2010.

  1. alphaod macrumors Core

    alphaod

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    #1
    Recently I revamped my computer. I bought an Areca 1680 with 2GB of cache and 3 120GB Vertex 2 SSDs.

    I have the 3 SSDs striped in RAID 0 on the RAID card and my old 4x 300GB VRs in RAID 5 on the same RAID card. The old drives in RAID 5 on the new card seems faster, probably due to the extra cache, but the SSDs are weirdly slow.

    With Quickbench, I can't seem to push past 500MB/s for reads and 450MB/s for writes.

    I'm pretty sure 2 drives can push those numbers. I know it's not a south bridge issue and the RAID card is in the second PCIe slot.

    Could it be my stripe size? Right now I have it set at 64KB.
    Write back cache is enabled and TCQ is disabled.

    Please advise.

    (For reference my RAID 5 gets 205MB/s read and 370MB/s write for a 4GB file)

    TIA.
     
  2. VirtualRain macrumors 603

    VirtualRain

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    #2
    I recall reading in the early days of SSD's that there were problems with the 1680 and SSD's as the card was optimized for SAS drives. I think it may use emulation to communicate with SATA drives? (Nanofrog would know! :)) I'm not sure if that's still a potential problem here? Perhaps Areca addressed that through a firmware update? At any rate, it's worth checking that you are running the latest firmware on your card.

    It seems Anand also ran into some SSD throttling issues with a 1680 in their testing awhile back... with 4xSSD's they were only getting about 3x throughput...
    http://www.anandtech.com/show/2739/5

    You might benefit from searching the OCZ forums where there's a lot more hardware combo's that have been run through the ringer...
    http://www.ocztechnologyforum.com/forum/forumdisplay.php?233-OCZ-Flash-Support-And-Discussion-Forum

    Also, you should run a 128KB stripe size, although that will only show any difference in write testing where write amplification will be an issue.
     
  3. alphaod thread starter macrumors Core

    alphaod

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    #3
    Thanks.

    Yeah I have the lastest firmware and everything. I made sure of that first thing after installing the card.

    As for the stripe, can I change this on the fly? I know you can do it with some cards, but will it support the change on this card?

    EDIT: Looks like I can change the stripe on the fly. That's pretty impressive.
     
  4. Honumaui macrumors 6502a

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    #4
    when I was playing with the 3 40 gig OWC SSD before I put them in their final location on two computers I dropped them on my Areca 1222x

    here is what I got

    might be worth running them on aja with my same settings and you can get a better idea ? these are 40 gig but are still quick in single mode about 225 MB/s
     

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  5. alphaod thread starter macrumors Core

    alphaod

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    #5
    Do you think I have a firmware issue?

    I get 498MB/s write and 520MB/s read with 3 Vertex 2s
     
  6. Honumaui macrumors 6502a

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    #6
    3 of my 40s on the ICH were write 475 read 553

    Nanofrog might shed more light ? but something is funny

    I am better at knowing programs and setup and such not as good on the firmware and technology that drives them ? more the one who can put together good setups if that makes sense :)


    would try http://www.xtremesystems.org/forums/forumdisplay.php?f=62
    also see what you can find ?
     
  7. VirtualRain macrumors 603

    VirtualRain

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    #7
    Everything I could find (and there isn't a lot out there) on the 1680 seems to indicate that it doesn't play well with SSD's... what led you to consider this card with SSDs in the first place?
     
  8. nanofrog macrumors G4

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    #8
    They're not consistant from what I've seen, so drive selection seems to be even more particular than mechanical (no SSD's listed on the HDD Compatibility List that I recall).

    And there are better cards for SSD's, particularly now (6.0Gb/s versions from Areca and ATTO). Of Areca's older cards, the ARC-12x1ML models seem to be decent from what I've seen (tested with Intel's SSD's prior to the Sandforce based drives being available IIRC).

    alphaod:
    Enable TCQ, then re-test (may make a positive difference).

    Then experiement with the different stripe sizes and see what happens (your results are slow). Ultimately, you may be screwed here, but try the setting changes and see what happens (the only SSD I know the right stripe size for is Intel, as the other makes don't publish sufficient information).
     
  9. alphaod thread starter macrumors Core

    alphaod

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    #9
    It was an open box item on NewEgg for $600. :eek:

    Enabling TCQ didn't help. Stripe size changes didn't help much either. Basically the smaller the stripe, the slower it was.

    Here's the weird part. I have 2GB of cache with write back enabled (with a battery). So I would assume any write less than 2GB in size would mean really fast speeds since everything is being dumped into what is essentially a RAM disk.

    Of course that doesnt happen. That's limiting me to 500MB/s.
    If I disable write back, the SSDs drop to only 200MB/s—that's slower than one drive. I'm really at a loss.


    In fact I find any drive connected to the card is slow… could this controller be defective?
     
  10. nanofrog macrumors G4

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    May 6, 2008
    #10
    Given it's an open box purchase, it's possible (why it was sent back to newegg in the first place, and they didn't thoroughly test it out before putting it back up for sale as "Open Box"). :(

    I didn't think it would, but it's always a good thing to try in general. As it happens, Intel's published enough information on those drives to determine the optimal stripe size is 128K. Other SSD's however, don't, so you have to experiment (haven't heard back from those that have them, so I don't know what setting for other controller makes; i.e. Sandforce).

    As far as listed performance data from benchmarks, Yes (results reported are based on a cache write, not disk, as it thinks the operation is complete). This is why you can get unrealistic numbers at times (when the cache is larger than the total capacity being written).

    The card may be bad, but there's a few other things you can try first.

    1. Re-flash the card with the latest firmware (even if it's the most current already, just in case there's been a glitch in the past).
    2. Re-install the drivers (even if you've the latest).
    3. You may even need to do the fresh driver installation on a fresh OS X installation (just in case there's some strange interaction going on).
    4. Go through the settings again (no idea what you've get set, but have presumed there's nothing really strange set).

    BTW, I'm not sure of the version of OS X, but 10.6.2 was problematic with RAID, so make sure you're running the latest version (don't recall but gugucom has been having other issues with Intel SSD's on an ARC-1210, which is an entry level SATA model; drop-outs IIRC, not performance).

    If this doesn't work, I'd contact Areca, and arrange an RMA (they may want you to try some things first if you're vague, so give a detailed description of what you've tried to keep this as brief as possible; they've taken up to 3 days to respond in the past, but they do know what they're doing). You can also call (they do speak English, but they're located in Taiwan, so it's not the least expensive phone call you'll ever make... ;)).
     
  11. Honumaui macrumors 6502a

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    #11
    part of me is wondering if using SSD stick to the newertech cards and or the ICH and just a few or mix of the above ?

    OR stick to the 1880 series ? seems a mixed bag ? my 1222x I just put on to test and get numbers ?
     
  12. alphaod thread starter macrumors Core

    alphaod

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    #12
    I'm thinking of just returning the card now. Way too much of a hassle it has caused. I'll just RAID 0 the SSDs on the ICH; sure there is a limitation, but it'll still be higher than 500MB/s. I guess it's good I didn't sell my old RAID card yet.

    I've reflashed it, reinstalled OS X to test, redone the whole array, switched memory chips (different brands and sizes)… I'm out of options here.

    And yes I have called them as well over Skype. They are pretty helpful. Even Areca has told me my throughput is too low and it possible the card is defective.
     
  13. Honumaui macrumors 6502a

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    #13
    this is what I got with 3 in raid 0 on the ICH

    so will be curious what you end up with ?
     

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  14. VirtualRain macrumors 603

    VirtualRain

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    #14
    That may be a smart move. If you decide to go back to hardware RAID, the 18xx series is probably the way to go although the 1231 series seems to be hitting 800MB/s+ with SSD's from what I've seen.

    BTW, This is what I get on the ICH with 3x Intel G1 drives in RAID0... (I believe I'm throttling on sustained reads)

    [​IMG]
     
  15. nanofrog macrumors G4

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    #15
    At this point, I'd return it as well.

    As VirtualRain mentioned, there's better RAID cards (6.0Gb/s ports) for SSD's such as the ARC-1880 series, or the newer ATTO models.

    You may want to wait on the Areca's though, as there was a problem with the early cards in MP's (wouldn't allow the system to boot caused by an over current during the boot process). Areca is aware of it, and has a fix, but waiting a few weeks for newer supplies to reach vendors might be a good idea to be sure you don't get one of the affected S/N's (there's a thread on this that has the S/N range affected for the specific Models).


    You could contact Areca on this as well, to see if the newer cards are shipping yet.
     
  16. alphaod thread starter macrumors Core

    alphaod

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    #16
    I have set up an RMA to return the card; I have gone back to the ARC1212 which detects my RAID 5 without any issues. Looks like I can switch cards without losing my arrays.

    I have attached my 3 SSDs to the motherboard and currently restoring the system from backup.

    As with the ARC1880 series, NewEgg does indeed sell them, but I not willing to spend the $900+ needed for a decent 12 port model. $600 was pushing it already.

    Anyways I'll report back how the ICH RAID 0 works after the restore.
     
  17. alphaod thread starter macrumors Core

    alphaod

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    #17
    Okay I have redone the test.

    With the ICH RAID 0, I can achieve 470MB/s writes and 630MB/s reads.

    The reads are better, but the writes are better or worse… I'm not sure.
     
  18. nanofrog macrumors G4

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    #18
    Yep. One of the nice things about sticking with the same maker for cards (arrays are usually recognized between the different models). :)

    There's other sites, but given the situation, I'll presume that it has to come from newegg for now.

    Provantage has a better price for the cards (12 port version here), but newegg does have an 8 port model (ARC-1880i) for $600. Actually, the 1880 series is well priced compared to the 1680 family (have actually found them cheaper for the same port count, and they're faster cards).

    Must you have a 12 port model, when the ARC-1212 is only a 4 port model?
     
  19. alphaod thread starter macrumors Core

    alphaod

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    #19
    The only reason I went for the 1680 was because it had more than 8 ports. If I'm going to spend more money on another RAID card, I would need it to have external SFF-8088 ports for when I get a miniSAS enclosure in the future. I don't see many 8 port models that have an external port.

    Anyways, I would love to get the ARC1880, but I think for the time being I'm going to keep what I have and when my budget allows for it, I'll upgrade.
     
  20. nanofrog macrumors G4

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    #20
    Keep in mind, those external connectors share ports with an internal connector on the 1680 series, so you're not getting an extra 4 ports.

    What you're describing is called a Hybrid, and they're hard to find. The ATTO R348 is the only one that I recall off the top of my head that's this way (runs in a MP, including the ability to boot), but is only a 3.0Gb/s model.

    The newer 6.0Gb/s ATTO cards are more traditional (all ports are either internal or external).

    I'd recommend going this route in order to get the right card to start with (cheaper than having to upgrade cards everytime you need to make a change/upgrade).

    Personally, I usually go for 4 ports minimum over what I need initially for furture expansion (cheaper to just add/replace drives and enclosures when needed than deal with a new card too).
     
  21. alphaod thread starter macrumors Core

    alphaod

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    #21
    I was going to get the ARC1222 initially, but I didn't feel like spending any more money than I needed after buying a new Mac Pro, a bunch of VelociRaptors, a new GPU… yeah. Hindsight says I should have just gone for the card with more ports which is why I want a card now that has a lot more ports to make this hopefully my last purchase for this machine.

    I'll definitely go the route of the ARC1880, but again I will wait for my wallet to heal.

    Anyway, thanks everyone for your help.
     
  22. nanofrog macrumors G4

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    #22
    You can get by with what you have if I understand your recent posts and recall your system setup correctly, so I don't blame you one bit. :D

    :cool: NP. :)
     
  23. alphaod thread starter macrumors Core

    alphaod

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    #23
    Okay, after running this for a day, I've experienced 4 kernel panics.

    I have attributed them to the Apple RAID…

    Basically if I try to read or write too much data to the RAID on the ICH, it will cause a KP.

    This does not happen on any other drives and it does not happen in Windows. It also only started after installing the SSDs on the ICH.

    Is this suppose to happen? Am I hitting an IO bottleneck which causes the KPs?
     
  24. VirtualRain macrumors 603

    VirtualRain

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    #24
    That's bizarre. You are now using a RAID0 array setup using OSX Disk Utility? What app are you using to test it or stress the storage I/O?
     
  25. alphaod thread starter macrumors Core

    alphaod

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    #25
    I've used Quickbench, AJA, and Drive Genius to run tests.

    The IO part is really just a guess on my part.
     

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