Do you encrypt your time machine backup? I have never done so with my older iMacs but I chose to do it with this new setup. When I hooked up my new external HD for the first time it asked me if I want to encrypt and I chose to. What are the pros/cons to doing this? I know it will protect my data. Does it slow my Time Machine backup down or does it not affect it at all? I am working with a fully loaded 27" iMac ( i7, 3TB Fusion, 32gb Ram, 2gb Video) and am doing the Time Machine backup via USB 3. I am about 20 minutes into it and have backed up about 23 gigs so far. I will stop and start over though if you all think it will slow things down. Thanks for your time!