Can an external SSD match the Mac Mini's pricey inbuilt storage?

David wants a new Mac Mini but doesn't want to pay Apple's eye-watering price for a 2TB SSD

My general question is: can a computer that has some of its storage on an external drive with a fast connection (such as Thunderbolt) perform as well as a computer with the same amount of storage inside the computer?

To be specific, I have a 2014 Mac Mini, which is very slow. I am considering upgrading to the latest 2018 version, but I need at least 1TB of storage. Apple can supply the unit with up to 2TB of solid state drive (SSD) storage, but charges an eye-watering 720 per terabyte. If I bought an external Thunderbolt SSD for about 220 per terabyte, would I be likely to see any difference? David

The general question is easy: external drives are slower than comparable internal drives, because the interconnection itself adds an overhead. While you could have a faster external drive, it would be better to spend the money upgrading the internal drive, where possible.