Let me start by saying we are a 100% Apple outfit.  We love our Macs and Aperture is no exception.  When it came time to decide between Aperture and Lightroom, the choice after spending some time with both was obvious; one is made by Apple and the other is made by the same company who thinks Flash is stable on a Mac.  I digress.

I started noticing that my Aperture library was really starting to slow down, almost to the point of wanting to pull my hair out, and this is working on a dual quad-core Mac Pro running at 2.8GHz.  This led me to start doing some research.  This first post will focus on Managed vs. Referenced files in regards to storing your Master files in Aperture.  My next post will deal with Library/File/Volume fragmentation and what the best strategy is to avoid having your Aperture library become fragmented, thus slowing it down.

A little background
We use Aperture almost exclusively to store, edit and process all of the photos that we shoot.  We, of course, shoot all our images in RAW, usually with a Canon 5D Mark II and as a result each of our files is typically ~30MB each.  Up to this point, I’ve allowed Aperture to manage all of our files which has generated a singular Aperture library that exceeds 500GB.  There are several reasons why this was a bad approach and I honestly just didn’t take the time to think it through when I initially setup Aperture (I think I was just too excited to get started).

So why is Managed bad?

1. Data isn’t segregated.  If you lose a harddrive or the Aperture library becomes corrupted for whatever reason, there is a good chance you could lose not only revisions (Versions) but possibly your Masters as well.  This clearly isn’t good.  By utilizing a Referenced setup, you can effectively store your Aperture Library on one volume and your Master files on another.  This gives you much greater flexibility and also much greater protection.
2. Backups take forever. This is primarily due to the file fragmentation which I’ll touch on in the next post.  Try copying a heavily fragmented file that’s over 500GB and you’ll quickly see that you don’t have 6 hours to sit and let it do it’s magic.

Possible Solutions
(Arranged in order of Safety and assuming you are using a non-expandable system such as an iMac, Macbook Air/Pro, etc.)

1. If you don’t want to deal with external harddrives on a constant basis you could essentially use your internal harddrive but simply partition it into 3 partitions.  One for your installation of OS X, one for the Aperture library and one for your Master files.  The only catch, is that you’d need to ensure you don’t fill any of the partitions more than 60-70% with files (more on the following post dealing with fragmentation).
2. Use an External Harddrive in the same manner as the internal except using 2 partitions, one for the library and one for the master files.
3. Use an External harddrive for your Master files and keep the Aperture library on your internal harddrive.  This will allow for good data segregation and also make it easier to backup both your Master files and library as there should be less fragmentation to deal with (Once again, more in the next post).
4. Use 2 external harddrives.  One would contain your Aperture library and the other would contain your master files.  This is probably the safest option as you have 3 independent drives allowing for more redundancy.

What I didn’t address was having an external RAID setup which would be the ideal solution so that you are constantly having backups made of both your Masters and library, but really when you start getting into it there are a lot of solutions you could come up with.

The main point here is to use Referenced Masters, not managed.