SSD dives install in Promise Raid array

emeldahayemeldahay
Posted:
in Genius Bar edited January 2014
Forgetting about cost just now is there any reason why a promise array could not be fitted with SSD drives?



Thinking Promise VTrak E-Class SATA RAID Subsystem or similar.



???

Comments

  • Reply 1 of 5
    emeldahayemeldahay Posts: 4member
    any geniuses around to help
  • Reply 2 of 5
    hmurchisonhmurchison Posts: 12,425member
    Quote:
    Originally Posted by emeldahay View Post


    any geniuses around to help



    As long as it supports 2.5 inch drives I think it could be done (expensively).

    Depending on the SSD the limiting factor would be the 3Gbps SATA bus.



    A single fast SSD drive now can saturate a 3Gbps bus. We need 6Gbps a second and

    even that won't be enough for a SSD RAID system.



    Sickening ..in the best way possible
  • Reply 3 of 5
    emeldahayemeldahay Posts: 4member
    Quote:
    Originally Posted by hmurchison View Post


    As long as it supports 2.5 inch drives I think it could be done (expensively).

    Depending on the SSD the limiting factor would be the 3Gbps SATA bus.



    A single fast SSD drive now can saturate a 3Gbps bus. We need 6Gbps a second and

    even that won't be enough for a SSD RAID system.



    Sickening ..in the best way possible



    is it possible to saturate the promise array 3gbps bus with normal drives?



    Would a particular drive speed be required in the array?



    thanks for the reply!
  • Reply 4 of 5
    MarvinMarvin Posts: 15,326moderator
    Quote:
    Originally Posted by emeldahay View Post


    is it possible to saturate the promise array 3gbps bus with normal drives?



    Would a particular drive speed be required in the array?



    thanks for the reply!



    3Gbps would be 375MB/s - you get 10k drives that can do 145MB/s so 3 of them in RAID-0 should do it. Not much point in doing that on the consumer side though as you'll only get 90MB/s over FW800:



    http://www.promise.com/storage/raid_...sn1=40&rsn3=28
  • Reply 5 of 5
    hmurchisonhmurchison Posts: 12,425member
    Quote:
    Originally Posted by emeldahay View Post


    is it possible to saturate the promise array 3gbps bus with normal drives?



    Would a particular drive speed be required in the array?



    thanks for the reply!



    Yes look at how the Crucial SSD loses about 25% of its throughput performance when it's on 3Gbps versus 6Gbps.



    http://www.anandtech.com/show/3667/o...-mp-firmware/4



    Keep in mind this is a single SSD. There's probably not an affordable chassis in production that would let you reap the rewards of a few SSD in a RAID configuration without severely hampering throughput performance.
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