2006 iMac 5,1 ssd on PATA vs. SATA

Discussion in 'iMac' started by pembyfrank, Nov 30, 2013.

  1. pembyfrank macrumors newbie

    Nov 18, 2013
    going to put in a 128G SSD, now on this older mac if i put it on the PATA with an optical caddy would there be a noticeable performance loss vs putting on the SATA where there is ahci?
    reason is already have a full size HDD in the SATA bay and want to keep it inside. i have done some research into routing the sata connectors to the optical bay for the ssd and the routing the pata connector to the hdd spot with a pata to sata adapter however i am unsure how the hdd would get power in this setup although its clearly the better way if doable
  2. Brian33 macrumors 6502a

    Apr 30, 2008
    USA (Virginia)
    I had the same dilemma when I upgraded my Early 2008 24" iMac, which also has a PATA interface at the optical bay and has a SATA 3 Gbps in the HDD bay. I don't remember the exact numbers, but I decided that the PATA interface would slow down the SSD performance too much but would have little impact upon a HDD performance.

    So, I removed the original 3.5" HDD, put the new SSD into the HDD bay, and put a new 2.5" HDD into the optical bay using a PATA--SATA adapter. My decision was made somewhat easier because I wanted to increase the size of the HDD beyond the original 320 GB while I had it opened up. So for me it was mostly a matter of whether to buy a 3.5" HDD or 2.5" HDD.

    The operation was a success and I'm very pleased with it, but I haven't run benchmarks or anything. I made my own Fusion Drive with the two, and I figure this will extend my use of the system for a few years, easily.

    I found data-transfer numbers for ATA (PATA) on the Wikipedia page and compared them to the SSD capabilities.
  3. Twimfy macrumors 6502a


    Sep 11, 2011
    Interesting, I considered doing the same thing on my 24" and everyone told me that the PATA would be a considerable performance hit.

    I'd be interested to see your results if and when you fusion it as I may do the same thing.
  4. pembyfrank, Nov 30, 2013
    Last edited: Nov 30, 2013

    pembyfrank thread starter macrumors newbie

    Nov 18, 2013
    for both of you there would definitely be a performance hit as PATA is 133MB/s max and you have SATAII or III, but this older iMac is SATA I which is 150MB/s so they are close in max throughput, but AHCI enables random block reads which could further boost the SSD, which is particularly good at this.
    it would be nice to try both scenarios out and post the results, but i may just bite the bullet, hook the SSD up to SATA, and put the HDD in a firewire 400 enclosure which maxes at 50MB/s, less than half of the PATA but just gets er done, i wont invest any more into this machine beyond the flashed firmware ram upgrade, and the SSD

    thanks for the input, Brian33, i would definitely do the 2.5" HDD on PATA if this iMac were a couple years newer like yours, not really worth it what with the vintage video card soldiered to the board

    this is sortof at the limit of my understanding perhaps the performance loss of SSD on PATA is 'real-world' not that much for this vintage machine and i should just put the SSD there.. it wont happen for a week or so, so maybe someone else can chime in.. fun project anyway

Share This Page