My Early 2008 iMac alu 24" HD drive has finally died and I'm in the process of replacing it. I've also recently got a 2013 Mac Air. The MacAir SSD drive is small so I want to share the iTunes/iPhoto libraries and user files between iMac and MacAir.

It seems a 2013 Airport Time Capsule would be a good solution - I could have the libraries stored on the TimeCap 2TB drive (Mac Air will connect over 802.11ac WiFi & ethernet for iMac). I would get a SSD drive for the iMac.

Alternatively I could keep the libraries on the iMac drive and use wake for network access when the MacAir wants them (then just use TimeCap for Time Machine backups). I would get a Hybrid SSHD for the iMac.

I am trying to work out the pro's & con's of these two approaches. I obviously want to get the best read/write speeds.

Config 1: library on the TimeCap

  • iMac > TimeCap over Gigabit Ethernet: 40|42 MB/s (read|write)?
  • MacAir > TimeCap over 802.11ac Wifi: 27|23 MB/s?

Source: "Speed test on new 2013 time capsule" thread. These speeds are slow, but the iMac gets an SSD for OS & application files.

Config 2: library on the iMac

  • iMac Hybrid SSHD over SATA 3Gb/s: 158-190MB/s (not sure if those figures are only for SATA 6Gb/s)
  • MacAir > iMac SSHD over AirPort 802.11ac Wifi (wake on demand): ?

Seems like a more traditional setup. The iMac no longer gets a SSD but will have fast speeds for accessing the library files over SATA compared to Ethernet.

Are the quoted speeds accurate? Which of these approaches is best overall? The decision affects which drive I need to go and buy.

1 Answer 1


Although you have stated that you want the best read/write speeds, you should consider other factors as well.

1. Redundancy (-Time Capsule; +iMac)

  • With the libraries on Time Capsule, where would the backups of the libraries be? If you have not thought of that, then you must consider it. Having the libraries as well as their backups sitting on a single device, the Time Capsule, is not a good idea (even if feasible).
  • With the libraries on the iMac, you could dedicate the Time Capsule exclusively for backups and have better redundancy.

2. Availability (+Time Capsule; -iMac)

  • With the libraries on the Time Capsule, you would have them available anytime since the Time Capsule would be on all the time.
  • With the libraries on the iMac, wake on network access, which is sometimes not reliable and breaks (and sometimes requires a patch from Apple) would force you to use other methods to wake the iMac manually (search through the Apple Support Community forums for wake on LAN or wake on network issues that have happened even recently).

3. Speed (=Time Capsule; =iMac)

  • I do not have any practical numbers, and do not understand why the Time Capsule shows up so slow over Gigabit ethernet on the thread you pointed, but it may be a matter of time and a firmware update from Apple to resolve it.
  • Although the native speed over SATA looks nice when the libraries are on the iMac, do you really need such speeds for music, photos and videos? I think not, even if you're planning for a future when 8K UHD videos become common (with Apple supporting it) and you plan to have large video files. Even 4K UHD (and the currently common Full HD 1080p) can be easily streamed at the lower end of the speeds you have noted.

4. Cost

  • You would have to work this out yourself and see what you can afford and what makes sense.

Winner, in my opinion: Libraries on the Time Capsule with SSD for the iMac, plus another 2TB external drive connected for backups of the libraries on the Time Capsule. Back up the Time Capsule (entirely or just the libraries) from the iMac using a tool like Carbon Copy Cloner, SuperDuper! or Chronosync or using the Archive function from Airport Utility and an Automator script to make it periodic.

  • Thanks for such a cool answer! I hear you re: wake on access- never worked for me so far :). I wondered about cloud-based backup services for the library files and timemachine database, so that a copy is kept off-site protecting against theft etc.
    – MachineElf
    Oct 10, 2013 at 17:19
  • I'll accept this answer, just want to keep it open a little longer to see what others say.
    – MachineElf
    Oct 10, 2013 at 17:20
  • Keep it open as long as you want to. You can also add a bounty to attract more attention to the question.
    – M K
    Oct 10, 2013 at 20:47

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