External hard drive for Time Machine

Discussion in 'Mac Accessories' started by spookle, Jul 1, 2013.

  1. spookle macrumors member

    Joined:
    Nov 18, 2012
    #1
    Hi, I have a 500gb mac mini. I want to buy a good value usb external hard drive to use with time machine for a back up.

    I read somewhere that for time machine the external hdd should have more gb than the mini hdd.

    Is that the case or would a 500gb external drive work?

    I only use a tiny amount of my mini's hard drive so I don't feel like I really need 1tb. (Not even years down the line with my usage).
     
  2. opinio macrumors 65816

    Joined:
    Mar 23, 2013
    #2
    You didn't really define 'tiny' but 500GB should be fine if you only have say a 50GB OS (inc all files). It really depends on whether you edit a lot of data in between saves. For example a virtual OS like Windows will use a massive amount of the Time Machine drive.

    Really though, it is hard to get a 500GB drive these days, although there are still smaller 500GB 2.5" drives in that size. I would think you will probably find a 1TB is one of the cheapest on the market and not too far away in price from any 500GB you find.
     
  3. SandboxGeneral Moderator

    SandboxGeneral

    Staff Member

    Joined:
    Sep 8, 2010
    Location:
    Orbiting a G-type Main Sequence Star
    #3
    I have 2 iMac's and one of them has a 1TB HDD and I'm using an old 120GB external HDD for Time Machine and it's been working fine for a long time. I don't have nearly a TB on the main drive though, but it works.

    The other iMac had a 1TB HDD and I am using a 1TB external HDD for Time Machine. Now I have a Samsung 840 SSD, 500GB for the internal drive, still being backed up to the 1TB external HDD.
     
  4. spookle thread starter macrumors member

    Joined:
    Nov 18, 2012
    #4
    Many thanks, both of you. That is helpful information.
     
  5. crowe-t macrumors member

    crowe-t

    Joined:
    Feb 7, 2014
    Location:
    Satellite Of Love
    #5
    Shouldn't the external hard drive used for Time Machine be quite a bit larger then the computer's internal hard drive?

    I've used a Western Digital external hard drive for back up in the past and used the WD back up software. As I deleted things I'd also go in and delete from the external back up hard drive.

    Does Time Machine work differently?
     
  6. SandboxGeneral Moderator

    SandboxGeneral

    Staff Member

    Joined:
    Sep 8, 2010
    Location:
    Orbiting a G-type Main Sequence Star
    #6
    It doesn't have to be unless your primary drive is nearly full. It would just mean that it wouldn't store long-term backups, and you'd only have more recent ones available to you.

    I have one iMac with a 1TB HDD and it's being backed up onto a 120GB external HDD. But I don't have any more than 250GB being used on it.
     
  7. xraydoc macrumors demi-god

    xraydoc

    Joined:
    Oct 9, 2005
    Location:
    192.168.1.1
    #7
    The nice thing about having a drive for Time Machine that's much larger than the main drive is that it'll keep old versions of files for as long as there is space.

    For example, you edit a photo then a month later you discover you want the original. If your TM drive has space, it'll keep old versions of files. If it doesn't, it'll only keep the most recent version - so no ability to go back to a much older version of a file.

    Rule of thumb I read is 2x the size of the drive(s) you're backing up.
     
  8. colodane macrumors 6502a

    colodane

    Joined:
    Nov 11, 2012
    Location:
    Colorado
    #8
    In my opinion, a more meaningful rule of thumb is that the size of the backup drive should be 2X the amount of storage used on the main drive.

    Many people only use a fraction of the large TB sized drives that are common these days, so no need for them to purchase something in the TB range for external Time Machine backup. In this situation a solid state external drive for Time Machine can be economically attractive.
     
  9. xraydoc macrumors demi-god

    xraydoc

    Joined:
    Oct 9, 2005
    Location:
    192.168.1.1
    #9
    Perhaps. Until you decide to begin using, say, Aperture more or you add a boat load of home movies. Generally I feel average consumers or new computer users are not good at predicting how much space they'll use.

    Given the small price differences between a 500GB or 1GB HDD and a 2TB HDD, it's better to get bigger unless you're 100% certain that 100GB of space is all you'll ever use.

    I've met many people who are certain they don't require large amounts of fast storage, then they get in to iPhoto or something and start to complain that it's too slow or that they're running out of storage. If there's, say, a $50 difference between "good enough" and "better", spend the extra $50.
     

Share This Page