Forgive me if this is in the wrong place, boring or dumb..... I have a mid 2011 iMac with a 1TB HDD (I updated the Ram awhile ago to 20GB, if that ends up being relevant). I use the computer for mainly light activities....photos, some minor video editing, internet, word processing, etc. My photos library is around the 300GB mark (about 600GB everything together) and lately the computer seems sluggish. I run Time Machine on an attached external, backup the photo lib on my router that has a built in HDD. Recently I've been using Carbon Copy Cloner to keep a bootable copy in another location. I update that weekly or so when I remember. We plan on buying a MacBook Pro in the next year or so, but I've been hoping to breath some new life into iMac just to make it's use more enjoyable. My question is this: Should I try something like the Transcend 250GB thunderbolt external drive to make a boot disk with just the OS and apps to make the computer a little more snappy (around the $200 mark), should I buy a thunderbolt dock that will give me access to USB 3 and make it easier to move and backup data -based on research none of these seem to be bootable, I could be wrong, hopefully someone can correct me because that would make this decision a lot easier ($250 mark), should I do nothing? I'm basically looking to spruce up the iMac (without spending a ton - thunderbolt stuff seems so expensive), but purchase something that I will still be able to use if we buy a Macbook Pro. I'm always paranoid about the HDD going, and I'm most concerned about the photo library so I tend to go overboard on extra copies of that (everything else I could live without). Thanks for your time!