Am I better of purchasing SSD external?

Discussion in 'Mac Accessories' started by yalag, Dec 16, 2012.

  1. macrumors 65816

    Nov 18, 2007
    Recently I've been really frustrated with my iPhoto/iTunes performance where all those libraries are stored locally in my iMac (5400rpm harddrive). The size of those two libraries combined is roughly 300Gb.

    I'm trying to decide if it will be worthwhile purchasing a big SSD external drive. Will I see much gain? Will the external connection speed limit the speed of my SSD drive anyway? (Because I can't upgrade my iMac's drive internally). Thoughts?
  2. macrumors 68020

    May 27, 2008
    try a disk speed test on your internal.

    for externals you will be limited by the speed of the connection.
    speeds below are approximate.

    USB 2 = 30 MB/s
    FW 400 = 40 MB/s
    FW 800 = 80 MB/s
    USB 3 = 110 MB/s
    thunderbolt = 150 - 200 Mb/s

    most hard drives will get you in the 70-100 MB/s range
    SSDs will get you 150-250 MB/s
  3. macrumors 6502a

    Jul 1, 2010
    FWIW, I have a Thunderbolt external SSD on my 2011 iMac that I use for the OS and Apps. It is an OCZ Vertex 4 128GB...I consistently see read speeds of 360+ and write speeds around 350.
  4. macrumors newbie

    Aug 21, 2010
    I'm using a Lacie 1TB Thunderbolt SSD for boot and apps. Very pricey, but defintely noticeable performance boost. My 2011 iMac boots in abt 15 secs, write speed of 360mb/s, read of 600+mb/s :D
  5. macrumors 68000


    Feb 16, 2009

    Isn't that a very low estimate as most are in the 300-500 range?
  6. macrumors 68000


    Nov 15, 2012
    Yeah- about half the speed.
  7. macrumors 68020

    May 27, 2008
    i got the speed wrong for SSDs, not sure what i was thinking, i know better.

    but the basics of my post still stand,
    for an external, unless you go thunderbolt, you will never see the speed of an SSD
  8. thread starter macrumors 65816

    Nov 18, 2007
    Thunderbolt SSD are in the range of 300+ but I guess my question is, what speed is typical for a 2011 iMac internal drive?
  9. macrumors 68020

    May 27, 2008
    You can ...
  10. macrumors 65816

    Nov 29, 2010
    I bought two Crucial M4 SSD's to run in RAID 0 with my new Macbook Pro. The SSD's arrived before the MBP did, so for grins I stuck it in a USB 3.0 enclosure and hooked it up to my PC. I got about 192MB/s in that enclosure. That's plenty fast, IMO. It's not, however, the maximum speed in the SSD.

    In contrast, in the MBP under RAID 0 (which nearly doubles the speed, but reduce reliability) I am seeing speeds around 920MB/s. That's actually faster than SATA III can handle (which is 6gbps, or a little more than 750MB/s. Remember big B, byte, is different than little b, bit). RAID 0 usually nearly doubles the speed of a drive so it's safe to say these drives would operate at around 400+ MB/s on their own in a SATA III setup. So, inside a USB 3.0 enclosure, I'm running at virtually half the speed.

    BUT, I'm STILL running faster inside an enclosure, than a platter based drive.

    An SSD is quite a performance jump, but something else you could consider is an external RAID 0 enclosure. With a pair of 500GB or 1TB drives, you'll get very fast performance and it will combine the drives capacities (two 500GB drives = 1TB). This will be cheaper than an SSD of a fraction of the size. The caveat though, is that there is greatly reduced reliability. If one of those drives fail, you lose everything. With my MBP, I backup with time machine every day and only store important things on external drives (or in the cloud) until I can get them home and into my desktops RAID 1 system. If you have iTunes match and your entire library is in the cloud, or you have a safe backup of your library on another system, I'd say go for it. If it'll be storing the only copy of files that are important to you, RAID 0 is not the way to go.

    If you shop around, you can get a RAID 0 enclosure for about $80 (USB 3.0), and a pair of drives for another $150 for the set. All in all that's a lot more storage for the price of an SSD in the 256GB range (without the enclosure). If your library isn't very big, then the cheaper option is a small (64GBish) SSD in an enclosure. Just decide how much storage you need.

    Also, you may notice an increase in speed just going with an external drive anyway. I don't recall if you are using a macbook, but if you are, most if not all are equipped with 5400 RPM drives. These run cool and use less power, but they are slow. A 7200RPM desktop hard drive of a higher capacity (and thus more dense, usually meaning faster) will be much faster than your internal 5400rpm laptop drive.

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