Im looking to buy a used iMac. The first one is a 27" mid 2011 2.7ghz i5 with 16gb of ram and a AMD RadeonHD 6770M 512 mb and the other one is a late 2013 2.7ghz i5 8gb of ram and an intel iris pro 1536 mb graphics card. I want to be able to edit family movies 5-10 minutes long with Final Cut Pro x. That will be the most labor intensive work I will do with it. Which one will work better? Thank you in advance.