One or Two SSD drives in my new iMac?

Discussion in 'iMac' started by timinireland, Aug 21, 2010.

  1. timinireland macrumors member

    Aug 21, 2010
    Hello everyone..

    I decided to sell my PC parts off, and buy a 27" i5 iMac. (Hoorah! lol)

    I have 2 x 120GB OCZ Vertex SSD's

    My question is do I keep my 1TB HDD and install one of the SSD drives, then use the SSD as the main drive etc.. Or what I would like to do, is the way I had my PC setup, is by maybe removing the 1TB HDD and install both SSDs.. and running them in a RAID setup. By installing both, would it really make much of a difference in transfer rates, over only installing one?

    Only thing im not sure about is by having both drives in, would I be maxing out the transfer rates for the SATA.. ? and if i put both in, what SATA ports to connect them to? I read that there is a 3rd SATA connector?

    Thanks for reading.. Any help appreciated.. :)

  2. MrCheeto macrumors 68030


    Nov 2, 2008
    I don't know if there is an internal RAID solution for the iMac.

    Also, what size are the drives?

    The dual-drive iMac has one 3.5" and one smaller drive, I'm not sure of the size, that may be 2.5" or even less!
  3. timinireland thread starter macrumors member

    Aug 21, 2010
    They are 2.5"

    I had both of them in a 2009 Mac Mini where i had removed the DVD drive and used a specialised enclousure for holding it.
    They seemed to be running in RAID on it.. would that had been a software RAID? Im not that clued up on it on the Macs to be honest.

  4. bolen macrumors 6502


    Jul 22, 2008
    The only RAID solution in Macs (except for Mac Pro) is software RAID. It's faster than non-RAID but not quite as fast as hardware RAID.

    If you have two disks I would suggest that you run them in RAID for optimal performance, especially since you're used to the performance. :)

    You can always get an external FW800 drive for storage.
  5. wirelessness macrumors 6502

    Jun 20, 2010
    In the iMac you would use software RAID which works fine for RAID0.

    The one thing I am interested in is find out what the long term performance on such a setup would be because OSX does not support Trim and from what I understand the background garbage collection function of the Sandforce controller does not operate in a RAID0 configuration. People run Win7 don't care because they have Trim support. The read/write performance is much higher in RAID0 on these types of drives but OSX users need to worry about long term performance. Some Sandforce drives have 28% Over Provisioning which might be enough to override the lack of Trim support. The amount of OP can also be increased by making smaller volumes.

    There are a bunch of threads in this forum already about adding SSD drives and what it takes to mod the iMac 27 so I won't go into here. Basically to add an SSD you would need to access the 3rd SATA port on the back of the logic board. Something you would need to do whether going RAID0 or keeping the HDD w/ SSD for boot.

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