I've been running various models on a Mac Pro 2013 (8 cores, 32 GB RAM) at about 8 to 10 t/s for months. It's not fast, but it's more than enough for many actual tasks, in particular background tasks. An iMac pro will do just as well I suppose.
The sort of task you don't expect to end immediately. If extracting data from a bunch of PDFs takes 1 hour or the whole night, that doesn't make much difference to me.
It's not fast enough for auto completion and slightly too slow for chat (but bearable IMO).