

The only difference is that EFI binaries are removed in the amd64+mac version ( Source, answer #2) which allows the broken EFI implementation in Mac mini (2,1) to properly boot in BIOS compatibility mode. In addition, for a 64-bit installation, you must use an amd64+mac iso. The Mac mini (2,1) must be installed from DVD. If you have a different model, please go here and find the right wiki. Under Ubuntu, you can verify that this is the model that you have by typing at the terminal: sudo dmidecode -s system-product-name You may want to read about some of this model's quirks by reading information on the Mac mini 2,1 page. This page aims to describe the steps needed to fully enable all features of the 2nd Generation Mac mini (release date: late 2007) on Ubuntu 14.04 LTS Trusty.
