SSD in a Time Capsule?

Discussion in 'Mac Accessories' started by mneblett, Mar 16, 2014.

  1. mneblett macrumors 6502

    Jun 7, 2008
    It appears that my Time Machine backups over Gigabit ethernet are bottle-necked at the 2TB HD in my 802.11ac Time Capsule, at ~20MB/s (the HD write rate being ~160MB/s).

    When researching whether there would be any benefit from replacing the HD with an SSD, I found that the few threads on the subject said an SSD would be a waste, arguing that the SATA III HD interface in the Time Capsule is already a 6 Gb/s interface -- but it seems to me that the SATA III interface isn't limiting, because 6Gb/s (750MB/s) is still quite a bit above the ~450-550 MB/s rates of today's SSDs.

    In other words, it looks like SSDs would give me somewhere between 2-3 times the Time Machine back up rates of the stock HD (40-50 MB/s vs. 20MB/s over ethernet).

    So (other than the obvious cost issues), what am I missing that would result in my Time Machine backups not benefitting from installing an SSD in the Time Capsule?
  2. ColdCase, Mar 16, 2014
    Last edited: Mar 16, 2014

    ColdCase macrumors 68030

    Feb 10, 2008
    Isn't the bottleneck the GB ethernet which has about a 100 MBps max line rate when frames are sized efficiently, but there is a lot of protocol overhead that brings that down significantly to where, in the real world, a typical SATA hard drive can easily cope. As long as the internal drive can support 80MBps, Ethernet is the bottleneck. Its the narrowest point in the pipe.

    You may save some seek time with a SSD if several computers happen to be backing up at the same time.

    SSDs will draw much less power and generate much less heat, however.

    You want to see fast backups, backup locally to a TB performance RAID :)

    Now if you were using 10GB ethernet...

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