Please help me find the right RAID card

Discussion in 'SSDs & Data Storage' started by RevMen, Jan 10, 2017.

  1. RevMen

    RevMen Limp Gawd

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    I have an application that involves writing a bunch of records (10M+) to a Neo4j graph, and I'd like for this to happen in as little time as possible. I've moved from a spinning drive to an SSD and that has made a huge difference, but I'd like to take it a step further and put a pair of SSDs in RAID 0.

    The data in the graph isn't critical and is replaced often, so the fragility of RAID 0 isn't important. Write speed is all that matters and, as far as I can tell, disk write speed is still my limiting factor.

    I don't know much about server hardware or about hardware RAID, so I need some help figuring out what I should do.

    My SSD drives are a pair of Samsung 850 Pro (SATA III)

    My DB server is one side of an ASUS RS700D-E6/PS8 (acquired from someone [H]ere, thank you very much!). Memory and processors are all maxed out (gloriously).

    https://www.asus.com/Commercial-Servers-Workstations/RS700DE6PS8/ - Manual here

    The motherboard has the Intel ICH10R controller, which I understand is limited to <700 MB/s transfer, even with a stripe array of SSDs. The board gives me the option of using either the LSI or the Intel interface to the on-board RAID controller.

    The backplane is connected to the motherboard with individual 7-pin SATA connectors. The ends of the cables connecting to the backplane appear to be SAS connectors, but I can't get a good look at them and don't know enough about SAS to say either way.

    The motherboard has a single PCI 2.0 x16 slot available through a riser.

    The SATA cables coming from the backplane will easily reach any card I plug into the riser.

    OS is Ubuntu.

    I only need the two SSDs to be fast. Keeping my other drives connected to the ICH10R is fine.

    I'd really like to spend less than $300 on a card.

    Would an SAS RAID card be able to connect with the SATA cables coming from the backplane with the right adapter?
    Would I need different cabling to connect an SAS card to the backplane?
    Or is it better to just use a card that has SATA sockets?

    Is there any detriment to putting a PCI 3 card in a PCI 2 slot?

    I could, conceivably, put the whole system on a 4-member striped array instead of data only on a 2-member array (after I get money for 2 more drives). Would there be an advantage to this?

    Can you think of a RAID card that would be a good fit for me?

    I look forward to receiving your wisdom.
     
  2. brutalizer

    brutalizer [H]ard|Gawd

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    Maybe there are some speed limitations on raid cards? I recon that if you use ZFS with NVMe disks, then you get full pci-express speed which might beat a raid card?

    One raid card occupies one pci-express slot. If you connect several SSD to the single card, the card is the limiting factor. If you use ZFS, then you connect each disk to each separate pci-express slot, which beats one pci-express slot.
     
  3. RevMen

    RevMen Limp Gawd

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    Only one slot available.
     
  4. criccio

    criccio Fully Equipped

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    Wouldn't a single M.2 (assuming it's available) or just a single PCI-e based SSD negate the need for a RAID card?

    That being said, I looked through this article to get some idea's about what's considered the fastest. http://www.tomshardware.com/reviews/sas-6gb-raid-controller,3028.html

    They're quite pricey. This one is around $320 on Amazon: https://www.amazon.com/gp/offer-listing/B005MJ8YHU/ref=dp_olp_0?ie=UTF8&condition=all

    As for cabling, you'd need something like this SFF-8087 breakout cable. http://www.newegg.com/Product/Product.aspx?Item=N82E16816116097
     
  5. RevMen

    RevMen Limp Gawd

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    Yes, but I've already got the 2.5" drives. If I was starting fresh, this is the way I would go.

    Although... if I'm willing to spend $300 on a raid controller...

    Thanks, I'll look into this option.

    I don't think that cable would work. I need to either plug the SATA cables from the backplane into something or plug something into the non-SATA plugs on the backplane.
     
  6. drescherjm

    drescherjm [H]ardForum Junkie

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    You can get LSI rebands on eBay for a lower price.
     
  7. RevMen

    RevMen Limp Gawd

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    Samsung 960 EVO M.2 with a x4 PCIe adapter should be 20% faster than my two 850 Pros in RAID. And it's much cheaper. That's the obvious solution.

    I'll just use my 850s for other things.
     
  8. rat

    rat [H]ardness Supreme

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    Ayup. IBM M1050 cards are LSIs and can be easily reflashed to go into IT mode for circumstances where the RAID is not done on controller. Well supported in BSD and Linux, too. Usually about $100 on eBay.
     
  9. rive22

    rive22 [H]ardness Supreme

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    How much space do you need? A RamDisk is a great way to go if it will fit.
     
    Shadohh likes this.
  10. Mackintire

    Mackintire 2[H]4U

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    Evidently there is a version of Samsung Magician software that runs on Linux. Using that you could reconfigure your 850 pros to pull well over 100k IOPs in exchange for longevity