Purchase RAID card or new SSD?

Discussion in 'Mac Pro' started by alphaod, Dec 14, 2011.

  1. alphaod macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #1
    I currently run 3x SSDs in RAID 0 for my boot volume. They are software RAIDed, so they are of course limited in speed by the Mac Pro chipset to about 500MB/s. They are 120GB SSDs each, so overall I'm looking at 360GB of space with about 100GB free at the moment. I wish to upgrade to Lion so I can migrate my MobileMe account to iCloud (and take advantage of all the new features). Plus I'm reading about potentially new video cards from ATi, but I'm afraid I would need Lion to run them.

    I have looked into it and it doesn't look like Apple will fix the Lion RAID issues anytime soon if ever, so I've sold on the fact that I need to do something on my end now.

    I'm currently considering one of two solutions:
    1) Purchase a RAID card that supports my SSDs and therefore I would not need to worry about Lion compatibility. I currently have an Areca ARC-12xx for my VelociRaptor RAID 5, so I don't have to migrate that as well, I think my options are limited to the Areca ARC-1880 cards. I think my current battery is in need of replacing as well as it's just old and doesn't really hold a charge (well it makes do for the time being). So overall I'm looking at spending $800-$1000 for the card, batteries, etc.
    2) Purchase a new SSD. It doesn't have to be SATA 6Gbps since that would require a new controller as well. Due to my current usage of 260GB, I think my only viable solutions are 300GB+ SSDs namely the 400GB SandForce based ones or maybe the Intel 510. That's about $800-$1000 as well depending on what I buy.

    For the first solution I can sell my current RAID card for some moneys, but I don't think I'll get much.

    For my second solution, I don't see a bunch of old 120GB SSDs selling for much either. And there is 3 of them to get rid of. I also see an issue where I am limited to about 280MB/s of throughput on the SATA 3Gbps cable.

    What are folks thoughts on this?
     
  2. wonderspark macrumors 68030

    wonderspark

    Joined:
    Feb 4, 2010
    Location:
    Oregon
    #2
    My roommate wants to move his MobileMe to iCloud, too. He's also afraid of Lion, and he doesn't have any SSDs or RAID to worry about! :p

    Anyway, does Lion not work with the SSDs you have now, nor work with the 12xx? If that's the case, don't you have to replace both? I guess I'm missing something here. How is it one or the other?
     
  3. alphaod thread starter macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #3
    From what I have read Lion cannot create a recovery partition on a RAID 0 array. It will proceed, but after a day or so of use, the OS will "freak out" so to speak. I cannot deal with my Lion dying after a day of use. Lions supports my SSDs if I use them individually (non-RAID) and Lions supports my controller. The issue my controller won't support my SSDs.

    My problem is I cannot upgrade to Lion because my current setup is a software RAID 0 which Lion doesn't support. If I use a hardware controller, the Mac Pro will only see the array as one drive hence I would have no issues.

    My current controller does not work with SSDs for whatever reason, so to use the "hide the RAID from Lion" solution is to use a RAID controller, but it needs to support the drives to work. A controller like the 1880 should work.

    If I buy a new drive, I don't need a new controller as I wouldn't need RAID 0 support anymore.
     
  4. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #4
    Striping disks only increases the sequential performance, and unfortunately, booting relys on random access performance.

    So even if you add another SSD with your existing models, it won't improve things (theoretically, random access performance would multiply as sequential throughputs do, but that's not the case in the real world).

    So you've a couple of choices.

    1. Get a single SSD with sufficient capacity that's faster than your existing drives for random access.
    2. Use a RAID level that actually improves random access performance.

    In the case of using RAID, there's a couple of levels you might want to consider; 10 and 5. At least the MP can do 10 without the need for additional hardware, and you shouldn't throttle for this (i.e. good SSD might see 70MB/s for random access throughputs). RAID 5 is even better, but would require both a bootable hardware RAID controller, but also SLC based disks if you're writing to it often (parity writes increases the write cycles to SSD's, and MLC isn't designed to handle parity based arrays).

    So 10 would probably be more attractive due to cost reasons (assumes you just buy one additional disk and use the existing 3 in the set), thus on similar ground to just using a single, larger and faster SSD as the boot volume (and possibly an inexpensive 6.0Gb/s bootable SATA controller if you can find the right model).

    Something to think about anyway. ;)

    • BTW, which Areca are you running?
    I ask, as 10 would be even better run off of that rather than Disk Utility (possibly even 5 if your write cycles aren't going to be crazy; if the primary data is on a separate volume, this would be possible using MLC based disks). And if it's a 12x1ML, would definitely be the way to go.
     
  5. alphaod thread starter macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #5
    I don't care about boot performance. I don't shutdown my Mac Pro ever. I only reboot it occasionally for updates. What's funny is that I have so many damn drives in my computer that takes 30 seconds or so to get past the bootloader screen.

    I'm thinking one of the new 480GB SandForce-based SSDs (ie: OWC Electra) would do the trick of replacing my existing SSDs.

    If I use RAID 5, that would increase my costs beyond what I would be willing to spend on this computer. I need money to buy the next Mac Pro you know!

    The ARC-1212 which only has one port, so even if it did support my SSDs I couldn't use it. Don't even get me started on why I cheaped out on this one.
     
  6. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #6
    Understandable.

    That's why I mentioned using 10 with your existing drives (just need to get another disk to make a 10 = cheapest way to do this that will also improve random access performance), or go with a single, larger, faster SSD, such as the OWC you're looking at.

    If you don't care about random access, then the OWC may be a better choice, as it will free up SATA ports if you pull the existing SSD's (though I expect you'll find another use for them...).

    But if you do decide to pull them, you can send them my way. ;) I'll accept a donation. :D :p

    Bit odd... (didn't know that model had issues with SSD's, but it is a feature-reduced product to make it's price point).

    I know some of the older cards, such as the ARC-1210 doesn't do well with SSD's, but the ARC-1212 is based on the Intel IOP348 running at 800MHz, which is the same controller in the ARC-12x1ML series, which do work with SSD's. Guess they cut more out of it than just SAS Expander support.

    I assume you're running the latest firmware revision. If not, get the general version (main support page), flash the parts (if you don't know the order, I'll get that to you), then update the EBC portion as that may also be newer (download this from the ftp site).

    I realize you're considering another system, but keep in mind, that even if you do spend money on a new RAID system, that can be transferred to a new system.
     
  7. alphaod thread starter macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #7
    The problem with RAID 10 is the same issue I have before. Lack of Lion support. The fracking lack of striping support in Lion. If do RAID 10, I would still need a new hardware controller and another SSD.

    I have the latest firmware and I had to learn how to flash the controller when I purchase it because it didn't come with EFI pre-flashed. I have also tried the ARC-1680 and didn't support my SSDs either. Honestly whether or not my current controller support SSDs or not is a moot point seeing it only have 4 connections and all 4 are attached to HDDs in my RAID 5.

    If I want to do RAID, I need a new controller, regardless to which RAID level I use.
    If I buy a new SSD, no need for a new controller, since I won't be RAIDing anything else but my existing drives (which is supported in Snow Leopard, which I imagine is non-issue in Lion).
     
  8. nanofrog macrumors G4

    Joined:
    May 6, 2008
    #8
    I'm a bit lost here in terms of what you mean by "Lion Support".

    I'm under the impression the Recovery Partition is what's giving you problems, but from what I recall from others, is that it still does RAID levels in Disk Utility without the Recovery Partition support.

    What I'm not sure of, is if they had to do something in order to disable it/delete it (there's something on this here in MR).

    Had to ask is all.

    I've helped others figure out how to flash the EBC file, but they may not have realized that the rest of it needs updating from time to time as well, let alone the order the sub-parts need to be flashed (i.e. download standard version, unzip, then flash each part in the correct order; the order is located in the manuals, not everyone reads it that closely, and even if they do, it's not the easiest/clearest manual to understand).

    Given the data array is on the Areca, and it's not working with SSD's anyway, I was referring to the ICH's SATA ports and using Disk Utility to create a 10, if you decide to go that way (ICH applies to the single disk option as well).

    I apologize that the ICH port aspect wasn't clear (thought you'd figure that one out given the card won't even work with SSD's). :eek:

    Me and my assumptions to save time typing. :eek: :p
     
  9. Schismz macrumors regular

    Joined:
    Sep 4, 2010
    #9
    Not really sure what you mean by "freak out"? I tried to install Lion the .0 version on a RAID0 and it just totally hosed everything. While some people seem to have experienced no trouble whatsoever, in my case, "Cannot create recovery partition on RAID drive, continue with install?" really meant, "Destroy everything, completely? Click OK to continue!"

    I gave up, installed to a single HDD, and then cloned it back onto a RAID0 boot using CCC.

    I'm booting with dual 240GB OWC 6G SSDs in RAID0, and have been using these since August with no problems, no weird hiccups and no freaking out (unless I mix too much Adderall with my LSD, but that's just my brain, not my drives. Those work fine).
     
  10. alphaod thread starter macrumors Core

    alphaod

    Joined:
    Feb 9, 2008
    Location:
    NYC
    #10
    Thanks for all your responses.

    I have been away from my desktop for a month. Anyways when I get back I'll be upgrade to a single SSD. I think a 480GB model should do nicely. Probably the OWC Electra/Mercury SSD.
     

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