NAS or Mercury Elite-AL Pro QX2

Discussion in 'Mac Pro' started by Dapness, Nov 26, 2010.

  1. Dapness macrumors member

    Jan 8, 2008
    I bought a Synology DS410 and like it but I'm not sure if it's the best thing for what I want to do. For some reason I thought I could run it in RAID 5 and back up my Mac Pro with it AND use it as a media server for my Mac Mini (Plex) and my WD Live TV. After the Time Machine backup was done I wasn't really sure where to direct Plex and my WD Live TV for the media. I never used Time Machine before and it seems great if backing up your data is what you want to do but I need folders for streaming.

    I decided to scrap Time Machine and just do a RAID 5 setup with DLNA enabled so I was left with folders for Music, Video, and Photos. Ok, that's better but I'm almost thinking there's a cheaper solution.

    That's where the Mercury Elite-AL Pro QX2 comes in. For almost half the price I could have an external RAID enclosure hooked up FW800 to my Mac Mini (on all the time) which could serve the files to my other computers and my WD Live TV. From my understanding FW800 and Gig Ethernet are comprable in speed so I wouldn't be losing much there if at all. The Synology has quite a few nice extras but I don't see myself really using them. I really just need a 4 bay external backup for my Mac Pro that can flawlessly serve up MKV Blu ray rips to my Mac Mini and my WD Live TV.

    Please, no Drobo suggestions. I completely understand that they work great for some people but they're overpriced for their performance in my opinion ;)
  2. khollister macrumors 6502a


    Feb 1, 2003
    Orlando, FL
    I am a little puzzled by what you are trying to do - are you looking to use the same volume as both a Time Machine backup and a media share for your Mini?

    How much media are you trying to share and how big is the data you are looking to back up with TM?

    The QX2 is a nice unit, but there might be cheaper, simpler options depending on the amount of data.
  3. philipma1957 macrumors 603


    Apr 13, 2010
    Howell, New Jersey
  4. nanofrog macrumors G4

    May 6, 2008
    The unit you lined is software based (card is just an eSATA card). This is fine for 0/1/10, but not a parity based array (5/6, though 5 is all that's usually available for for such products) due to the write hole issue (solution = hardware only).

    The Qx2 uses an RoC (RAID on a Chip; Oxford 936 in this case), that can at least handle RAID 5 properly.


    You could also opt to use a proper RAID card and an external enclosure (runs parity based arrays properly, as it has the NVRAM solution to the write hole issue), and you can exceed the 4x disk limit with the Qx2. Such a solution would also be faster than the Oxford (faster processor and cache will pick up the throughputs for the same disks).

    One note however: if you do get a proper RAID card, you must run enterprise mechanical disks due to how recovery is handled (consumer disks are not stable under such cards).

    There are other options as well, such as a DIY NAS or SAN.

    One example would be to use a cheap system (dedicated for this purpose, so no need to go crazy on price; ITX sized board can suffice, though M-ATX is much easier to find) running Linux or Open Solaris. Setup either a Z-RAID or Z-RAID2 (equivalent to levels 5 and 6 respectively, but without a write hole so software implementations are fine), and transport data to/from the MP via iSCSI or ATA over Ethernet (AoE). No special hardware needed. :D Assuming there's a way to add SATA ports, you can scale the system for capacity (throughputs are fixed due to the Ethernet port/s). Faster networking (10G Ethernet or Fibre Channel) would do the trick, but it will add money to the system (need a card on both ends; assumes no other systems to be connected to the storage solution so no switch or router is needed).

    From what you've posted, super high speed's don't seem to be a primary concern, so you'd be fine if you go this route.
  5. Dapness thread starter macrumors member

    Jan 8, 2008
    Thanks for your input. I'm now looing at a 4 or 5 bay tower enclosure from San Digital. These look really cost effective and have hardware RAID built in. The Synology NAS I have just seems like too much for what I'm trying to do. $500 vs. $150 is a big difference.

    I have an Airport Extreme Base Station so I can plug the enlosure into that via USB2 (yuck) and stream media to my Mac Mini HTPC (wired connection) and my WD Live TV Plus (wired conncetion). I'm currently testing whether or not this setup would work for flawlessly streaming high bit rate MKVs. I tried Minority Report (~45 gigs) and it seemed to hold up ok. Any thoughts??

    1) Could I also ulilize the eSATA port and also plug it into my Mac Pro using the provided eSATA card for greater transfer speeds between the Mac Pro and the enclosure?

    2) What is the difference between this and the OWC QX2 I was looking at besides the interface options. Now that I look at it the QX2 does seem pretty pricy in comparrison to this for what it offers unless I'm missing something.
  6. Dapness thread starter macrumors member

    Jan 8, 2008
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    Actually Minority Report didn't fare as well as I'd hoped. I ended up having multiple issues with playback. Definitely bandwidth related in my opinion. Ughhh, back to the drawing board :/
  7. nanofrog macrumors G4

    May 6, 2008

    The Sans Digital units do not have built-in hardware. They're software based (uses system resources to do the work).

    If you want the RAID handled via hardware within the enclosure itself, you're going to have to spend more. The Qx2 is the cheapest 4 bay unit I can think of (others are more expensive, though faster and likely more robust in terms of recovery options; these are typically over $500 USD for anything you'd actually want in a 4x bay unit, $1k USD for an 8 bay unit).

    USB2 would leave a bit to be desired for uncompressed 1080p (MKV spec doesn't include a compression scheme).

    FW or eSATA would be better suited in terms of bandwidth (real world throughputs are higher than what is needed for 1080p). :D

    Provided the enclosure uses eSATA port/s and the card supports Port Multiplier chips (if the enclosure has one - not an issue for a single disk), then Yes.

    For what you're trying to do, the Sans Digital enclosures do use PM chips, so the card must support it (card in their kits do, or it wouldn't work - those cards also work with OS X; they just won't boot OS X, which you don't need for a movie library).

    The Qx2 has a hardware RAID controller in it (simple, but it's still a hardware RAID controller on a Chip; aka RoC).

    The Sans Digital enclosures do not have such a chip. It's just a Port Multiplier enclosure + eSATA card. Any RAID support is provided via software (either via Disk Utility or 3rd party drivers if provided and you wish to go that route).

    As it happens, if you want to run a redundant level under Disk Utility, you'd want to run level 10 (4x disk set would give half the total capacity, at 2x the performance of a single disk).

    Do not attempt to run a level 5 array via a software implementation (you're risking written data to be corrupted during the write process if you do). Why the write hole issue is a problem for software implementations.
  8. hpr macrumors newbie

    Oct 10, 2007
    I have a TR5UTP from Sans Digital ( ) with 5x 1.5TB drives in RAID5 and it runs a treat and has a RoC built-in. It comes with an eSATA card but I just used the port extender included to pop one of my spare internal ports to the outside. The only complaint I have with the enclosure is the PSU fan whines. But I have unplugged it until I get a quieter 40mm fan for it. (Temps weren't affected by unplugging the fan, there seems to be enough airflow from the rear fan.)
  9. nanofrog macrumors G4

    May 6, 2008
    When I saw the Highpoint RR622 as the included card (same as the Port Multiplier versions), I didn't investigate further.

    But since you posted, I checked again, and it does have DIP switches on the back for setting levels. So there's an RoC of some sort in there.

    Good to know (similar to the Qx2).
  10. Dapness thread starter macrumors member

    Jan 8, 2008
    Just a little update in case anyone gets into the same situation I was in.

    I bought the Mercury Elite QX2 4 Bay unit for $270 from OWC. I have it hooked up via FW800 to my Mac Mini which I pretty much exclusively use for Plex. Since the Mini is always on it acts as a server. The QX2 is running RAID 5 which was a breeze to set up. It only took most of a day to format and transfer all the data as opposed to the Synology NAS which literally took 3 or 4 days.

    The Synology NAS was my first experience with a NAS and while intuitive it was still a little more complex than I desired. With the QX2 I have redundant external backup and I can stream media to anywhere in my house. Simple, cost effective, and energy efficient.

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