2.5" vs 3.5" external hard drives, which is more reliable?

Discussion in 'Buying Tips and Advice' started by ElDogman, Feb 15, 2010.

  1. ElDogman macrumors 6502


    Aug 8, 2008
    although 3.5" hard drives give more space for the dollar, I'm more interested in long term reliability and life span of a hard drive. are there any significant differences between the two hard drive sizes? I'm guessing the 2.5" runs cooler and may benefit from a longer life?

    also which brands are good for 2.5"?
  2. Bengt77 macrumors 68000


    Jun 7, 2002
    Seagate is a very reliable brand. But then again, so are Western Digital, Hitachi and Samsung. I'm a Seagate person, though, but you have to know that probably neither of the four brands is better than the other. Some people have most trust in brand 1, while other people go for brand 2, etcetera.

    Desktop drives have the tendency to be more reliable. They've been in development for way longer, and the density can be lower, due to larger platters. That means that, in theory, there's less room for error in the manufacturing process. Plus, you can get enterprise class drives in 3,5". Well, you can get enterprise class drives with SATA-connectors, that is. I know that some brands also offer them in 2,5", but only with SAS-connectors, which you can't use in your personal computer.

    (Somebody please correct me if I'm wrong with my above statements, though.)

    With the following links you'll find Seagate's, Western Digital's and Hitachi's enterprise class drives. As far as I know, Samsung doesn't offer any.
  3. rgarjr macrumors 603


    Apr 2, 2009
    Southern California
  4. scottness macrumors 65816


    Mar 18, 2009
    Room 101
    I just get 3.5s unless I'm intending to eventually swap out with my laptop. They're cheaper, all else the same, I think.
  5. Badger^2 macrumors 68000


    Oct 29, 2009
    All drives fail.

    No matter the maker, no matter the size no matter the capacity.

    Once you learn to accept that fact and just buy whats on sale and/or fits your needs -- and have a backup -- then you will have one less thing to worry about.

    For every "I love XXXX drive" story you see you are going to see a "I hate XXXX drive" story. End of story.
  6. steve2112 macrumors 68040


    Feb 20, 2009
    East of Lyra, Northwest of Pegasus
    Amen! Too many people don't look at things this way. A couple of years ago, Google did a massive study on hard drives. They basically found that if the drive survived the first couple of months, there was a consistent pattern of drive failures. I forget the percentages, but they failed at a certain amount per year. One interesting thing they found was that heat levels and drive activity didn't have as much impact on the failures as they initially thought they would. The one thing that bugged me was they said something to the effect of certain makes and models were more prone to failure, but they didn't publish that info in the paper. They also don't use enterprise level SCSI drives. They used normal, off the shelf, ATA and SATA drives.

    Edit: To answer the OPs question: If you aren't going to be moving it, go with the 3.5", since they tend to be cheaper.
  7. lixuelai macrumors 6502a

    Oct 29, 2008
    I used to love Seagate until they put out the 7200.11s. Had so many fail on me.
  8. Badger^2 macrumors 68000


    Oct 29, 2009
    And there you go:

    Bengt77: Seagate is a very reliable brand.

    lixuelai: I used to love Seagate until... Had so many fail on me.

    And thats the end of the story I was talking about...
  9. foobarbaz macrumors 6502

    Nov 29, 2007
    There's no significant difference between hard disk sizes. If you want something really realiable, get two hard disks.

    Every other answer you'll get is hearsay or statistically insignificant.
  10. rickvanr macrumors 68040


    Apr 10, 2002
    Think of it this way

    2.5 external drives can be USB powered
    3.5 external drives next a separate power cord.

    So if you're going to move the drive around a lot I'd go 2.5. If you're just going to use it as a backup drive, and it's staying put on the desk, go 3.5. 3.5 also have much more bang for the buck

    I use both. I have a small external for going between computers, it's super easy to carry around, and then I have a big FW800 enclosure with 3.5 drives in it for backup.
  11. ucfgrad93 macrumors P6


    Aug 17, 2007
    Agreed. I have a Lacie external drive that I use with Time Machine. However, I don't believe that it is any more reliable than any other harddrive.
  12. student_trap macrumors 68000


    Mar 14, 2005
    'Ol Smokey, UK
    True, but at the same time manufacturers of drives seem to go through cycles of good and bad, for example, last years hitachis weren't up to scratch, while seagates drives seem to have taken a turn for the worse recently.
  13. muller93 macrumors newbie

    Feb 4, 2013
    I agree all the mechanical parts always fail
  14. monokakata macrumors 68000


    May 8, 2008
    Hilo, Hawai'i
    I think rickvanr's advice is worth taking: do you think you'll ever want bus-powered drives? They can be very convenient (like him, I have a few).

    If so, then 2.5" for you.

    If not, then I don't see any advantage for them.
  15. gnasher729 macrumors P6


    Nov 25, 2005
    I'd put my bets on the 3.5". In larger sizes, they are cheaper. There is an interesting option for Time Machine backups now: You can set up Time Machine to alternate between two drives. So you buy two cheap 3.5" USB drives, and even if one of them crashes, you still have a working backup.
  16. Panch0 macrumors 6502a

    Feb 23, 2010
    No significant difference in reliability. An additional positive for 2.5" drives is noise level. Since they generate less heat, their enclosures can be fan-less, which makes them quieter. The drives themselves seem to be quieter in operation, but it's the fan that makes the biggest difference to me.
  17. Gizmo22 macrumors regular


    Oct 22, 2009
    Midwest USA
    Personal preference is 2.5". I have a few 3.5" drives that I swap between a Orico enclosure (love by the way). Never the less, I do not have much data that I need constant access to. Plugging in once every few days or a week for Time Machine backups, and occasionally pulling a few Blu Ray ISOs if I think I'm going to watch a movie while on a trip.

    For that reason, I would really prefer a 2.5" drive that can be tossed on the shelf or in a desk drawer with much greater ease than a 3.5" drive that needs 120volt AC
  18. 1934hotrod macrumors regular


    Jan 27, 2013
    Must agree here and think seagate will fix that @ some point in time. Here is my story, bought a 1 tb external drive from uncle apple. The drive did not have 50 hours on it and went south. Click, click no spin up. Open the case and found it was a seagate, the very one apple has recalled for replacement. So I called apple lesson to be learned here folks. Told them I bought this drive from the apple web site, gave them the drive model #: st31000520as . Asked if they were would replace it because they were in the process of recalling this very drive?

    Here was the response, the clown hung up the phone, I did nothing but ask a very logical question and their response was childish and extremely unprofessional.

    Apple is fast becoming just another over hyped machine, this will not be in the companies best interest for the future. They are not to big to fail, and are about to get their feathers trimmed, the customer pays the bills. I have had apple for my home 96, ask me how many times I have called the tech support twice.

    Rock on,
  19. js81 macrumors 65816


    Dec 31, 2008
    Since most users have abandoned desktops for laptops these days, I think the 2.5" drives make a better choice than 3.5" drives (that require power adapters).

    BUT... I use 2.5" drives with my mini (desktop) because I can get dual drive enclosures that DON'T have to have a cooling fan. I like my nice, quiet Mac mini. :) And since they're fan-less, I can keep an immediate mirrored RAID backup of all of my most important files (the thousands of pictures of my new baby girl and my movies), as well as a Time Machine backup, too. Yeah, I'm a bit obsessive about backup.

    I do, however, have a couple of 3.5" single drive enclosures - one is my Time Machine drive, the other is a documents "archive." (I'm a bit of a digital pack-rat, lol) Not sure what I'll do when these need replaced, whether dead or full - I guess it all depends on prices and sizes at that time. For now, I'm good on both fronts.

    That all being said... I'm a fan of Western Digital. :D Haven't had a single failure of a personal WD drive in 20 years of computer use and repair/upgrade. (And being a tech-geek I've had PLENTY of computers and hard drives, both internal and external.)

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