I just bought a 1TB SSD and put in it an old laptop. Took the laptop about one week to download and sync the whole chain. It did this without me standing there and watching 😂
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It took me more than that, and I had to restart a couple of times. Not doing that ever again.
Now I can use *any* computer I want (right now, a 2016 one), and simply plug it in and be online in seconds.
There are literally ZERO arguments against keeping the block directory on an external SSD, or advantages of using an internal one.