Are they 200 - 300 workflow running at the same time ? or 200 - 300 different
published workflows ?
I think your
servers will be quite fine. I've had hundreds of Nintex workflows running at
the same time on server well below that spec.
you haven't mentioned is your Database server.. The quite pig in the room. Most
times where I've seen performance take a hit it has been here, and not so much
the SharePoint servers. SQL can slow the process down in a number of areas, not
enough RAM ( Remember, it will use as much as you give :) ) The CPU is max'ing
out, or your Disk I/O is off the chart. In the most of my cases it was Disk IO
where I was having performance issues, but this was SharePoint wide, not just
said all of that. What you have I believe will be fine, IF NOT, the workflows
will not bring your system to halt they may just Poll a little longer. And at
this time, you will be able to see your bottlenecks and diagnose accordingly
I hope all
of that made sense :)