Best external USB 3.0 HDD for iMovie

Discussion in 'Mac Accessories' started by spodlude, Jul 10, 2013.

  1. spodlude macrumors newbie

    Jul 10, 2013
    Norwich UK
    Hey everyone,
    I have a rMBP and occasionally do some video editing, however the files from the HD camcorder are massive and with only 256GB on the rMBP SSD I've nearly ran out of memory.

    I was thinking about getting an external USB 3.0 HDD to store the iMovie imports, would this work in real time for editing? I guess the correct term is a scratch disk? (If so how would I set this up in iMovies, and, do you recommend any specific drives, no greater than the £100 mark ($150)).

    Many Thanks,

  2. FreakinEurekan macrumors 68040


    Sep 8, 2011
    Eureka Springs, Arkansas
    You have a bunch of options, but one big differentiator - bus powered vs. self powered.

    Bus powered USB 3.0 drives don't tend to be terribly fast, but they can be used when you're out and about on battery power.

    Self-powered drives can use faster disks but need their own power supply plugged into the wall, so not very portable.

    SSD or partial-SSD high-speed options are available also, but not in your budget.
  3. Che Castro macrumors 603

    May 21, 2009
    Get a portable usb 3.0 wd drive , since you have a laptop

    You can get a 1tb
  4. Giuly, Jul 10, 2013
    Last edited: Jul 10, 2013

    Giuly macrumors 68040


    There's the Buffalo Drivestation DDR with 1GB of DDR3 cache (experience with it is limited but quite positive thus far).

    Alternatively a RAID0 of two disks attached via Thunderbolt, i.e. the Western Digital MyBook Duo Thunderbolt (or MyBook Velociraptor Duo Thunderbolt if you want ultra fast 10000RPM hard drives) and LaCie 2big Thunderbolt.


    If you have files >1GB to work with, the RAID0 will be faster, but is well beyond your budget.

    The 2TB Drivestation DDR is actually still within your budget, but it's questionable how well the DDR3 cache works with large video files.

    A 4TB WD MyBook Studio for Mac on the other hand gives you a fast hard drive with twice the capacity for $40 more than the 2TB Drivestation DDR, which might be worth a consideration depending on the amount of storage your videos require. If you move your current movies off the internal SSD, you should also have enough empty disk space to keep using that as the scratch disk.
  5. meistervu macrumors 65816

    Jul 24, 2008
    Large files are consisted of segments, and each segments are cached. A 1 GB cache is pretty huge and should make a big difference in term of performance.
  6. Giuly, Jul 10, 2013
    Last edited: Jul 10, 2013

    Giuly macrumors 68040


    Sure, but if you import a 5GB iMovie project, 4/5 of those segments are still on the hard disk, and chances are that the other 1/5 aren't (partially) cached. The performance increase here would mostly arise from writing small updates to the disk as you go, the question is whether iMovie even does that. My guess is that it imports the 5GB into the RAM (if available) and modifies it there while saving in the background, as that'd be the smartest thing to do. Remember, most Macs have 8-16 times the amount of DDR3, connected via something a bit faster than USB 3.0 and it caches files, too. The hard drive isn't anywhere close to the 5GBit/s of USB 3.0, so that's the speed at which both the 1GB in the enclosure and the cache in the Mac's RAM fill. Technically, due to the Mac itself using RAM to cache the mostly accessed files/sectors, the benefit of that thing should be zilch (more precisely, as effective as adding 1GB of PC100 SDRAM with a bandwidth of ~5GBit/s to the system).
    And 2TB vs. 4TB in the same price range is another thing to consider depending on the OP's priorities.
  7. meistervu, Jul 10, 2013
    Last edited: Jul 10, 2013

    meistervu macrumors 65816

    Jul 24, 2008
    Not knowing anything about how movie editing work, I am going go out on a skinny limb and say a 1GB DRAM cache on the hard drive can be used efficiently to speed up the process.

    Here is my thought: when you edit a movie, you edit frames. If a movie is 60 minute long, there is no need to load all the 60 minutes of frames. Instead, load the 10 minutes that the user is working on, and anticipate what the user want next and keep it in the buffer. In general, movie comes in different sizes. It would be rather limiting to assume that an editor will have to load the complete movie into RAM to edit it.
  8. spodlude thread starter macrumors newbie

    Jul 10, 2013
    Norwich UK
    Wow, thanks everyone, I wasn't expecting so much useful advice, so soon!

    Im going to save up the extra to purchase the Buffalo 2TB DDR Drivestation, It converts to £150 over here so considerably up on the budget. As you've all made clear: it needs to be fit for purpose with such large file sizes, so I think it warrants spending the extra.

    Thanks Again!



    I don't really use my laptop on the go for video editing, thats strictly a desktop affair; thus a powered drive is better for my circumstances, I guess, due to the increased speeds....
  9. Giuly, Jul 11, 2013
    Last edited: Jul 11, 2013

    Giuly macrumors 68040


    The problem is that "loading into RAM" and caching on some built-in 1GB RAM in an enclosure is the same thing when you have an operating system that provides a system-wide file cache via it's system memory already, and the Mac's internal 1600MHz DDR3 has not only a bandwidth 20x faster than USB 3.0, but also somewhere between 8-128x more of it. A Fusion Drive with an 1GB SSD wouldn't make that much of a difference, either.


    During installation of iLife '11, this just went up to 8GB so it also works as a write cache, the only advantage I've seen for the Drivestation DDR. It also went up during the download of the updates at the same rate as the download, so it caches those kind of things, too. I can also confirm that iMovie (even the version on the retail disk of iLife '11) loads the project into the RAM, as I can't hear or feel my trusty USB 2.0 hard drive seek after the initial import (which is instant for my 10-minute 720p test project).

    I don't see it to make a big difference because the Mac shouldn't access the hard drive in the first place, but keep the files/sectors/frames in it's own 'cache', and as far as I can (empirically) tell, that actually happens.

    So to conclude, I myself personally and IMHO, after getting an overview of what's going on and testing it to work fine with a relatively slow USB 2.0 WD Essentials (WD Green; 5400RPM) hard drive, would, for this particular purpose of storing iMovie projects and under the OPs budget, opt for the more capacious 7200RPM hard drive instead of the Drivestation DDR.
  10. opinio macrumors 65816

    Mar 23, 2013
    Seagate 3TB USB3.0 drives have exceptionally fast drives for their low cost. The 7200rpm drives in the enclosure come very close to velociraptor read/write speeds. The 4TBs are also fast but Seagate has started making 5900rpm drives instead of their original 7200rpm so the 4TBs are hit and miss with what you get.

    I get around 200MB/s read/write in black magic on the 3TB USB3.0

    Attached Files:

  11. Haifisch macrumors regular

    Nov 19, 2012
    I know the OP want to stay under a budget but is it worthwhile to save up for a Thunderbolt ext HD? I know that actual speeds doesn't come close to theoretical. Random websites say, depending on brand, that USB 3 is very close to TB, but the TB is more $$.

    Any experiences between USB3 vs TB?
  12. Macsonic macrumors 65816


    Sep 6, 2009
    There is this Youtube video were TB and USB 3.0, SATA were tested and compared HERE

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