Please help me find the right RAID card

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

  1. RevMen

    RevMen Limp Gawd

    Messages:
    354
    Joined:
    Feb 22, 2004
    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

    Messages:
    1,584
    Joined:
    Oct 23, 2010
    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

    Messages:
    354
    Joined:
    Feb 22, 2004
    Only one slot available.
     
  4. criccio

    criccio Fully Equipped

    Messages:
    10,685
    Joined:
    Mar 26, 2008
    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

    Messages:
    354
    Joined:
    Feb 22, 2004
    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

    Messages:
    12,868
    Joined:
    Nov 19, 2008
    You can get LSI rebands on eBay for a lower price.
     
  7. RevMen

    RevMen Limp Gawd

    Messages:
    354
    Joined:
    Feb 22, 2004
    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.