Speediest external drives for 1TB SSD iMac ?

[JamesPDX]

https://www.blackmagicdesign.com/products/blackmagicmultidock

You'll wonder how you ever got by without one.

 

[joema2]

Interesting insights - but I guess I meant the difference between a 2015 1TB SSD (with the future externals that will entail) and a 2015 3TB fusion drive

For typical still and video editing tasks, if using Thunderbolt external storage 3TB FD vs SSD generally doesn't make much difference. The lead editor's computer on the Will Smith film "Focus" was an iMac 27 with 3TB Fusion Drive, although he had an approx 32GB Thunderbolt array.

That said, I would generally get an SSD iMac if using external storage. Maybe it doesn't make a huge difference in real-world performance but it does help some, it's probably a bit more reliable (though nobody knows how much), and it may help if you are using Boot Camp or Parallels.

There is a valid "emotional" benefit to SSD, or any other top-spec configuration choice. If your system is slow at least you won't think "if I had only gotten that upgrade, maybe it wouldn't be so slow". You know it couldn't be any faster from a hardware standpoint and you focus your improvement efforts elsewhere.