John Siracusa briefly mentioned something in one of his podcasts that stuck with me and I want to get it in writing for future reference. Ideally, I would like to link back to where I heard this. The problem is that I cannot remember which episode or even which podcast — though I think it was Reconcilable Differences — for full acknowledgement, and neither podcast has a searchable text transcript.
The situation here is that you are moving from an old Mac to a new one, and you have reached the point in Setup Assistant where it asks if you want to transfer data. You agree, it opens Migration Assistant on your new Mac — you open it manually on your old one — and then it runs a few tests in the background to automatically select the fastest transfer method.
In my case, this was peer-to-peer at a painfully slow three-to-six megabytes per second. To move the half-million files from my old Mac, it was looking like a twelve hour operation. But I remembered I had a first-generation Thunderbolt cable laying around and an adaptor — and the tip Siracusa relayed in that podcast episode: Migration Assistant will automatically switch to the fastest method available, even partway through a migration.
So I plugged it in to both Macs and, I kid you not, all my stuff was moved over to the new Mac in the time it took me to boil water and brew a coffee. Remember, this was with a first-generation Thunderbolt connection. Imagine how much faster this could be if you upgrade your Mac more often than I do.