40x40 / 81x81 would be a slide show or slow motion fest with less than high clocked Quad Core with AI involved. Not sure with just human players
From personal experiance I can tell you 40x40 maps on a Q6600 @ 3.6 will slow down to about -3 with 2 human players and 1 Sorian AI (1000unit cap) when the units hit around 1600 - 2000. 81x81 hits -3 or -5ish at about the same unit count level (1600 - 2000)
Frame rate at this point on a GTX260 isnt great either....20 - 30 while hosting 1x Sorian AI
Hope that clears some things up.
Bring on Intel Core i7 !!
...I wonder if SumCom will scale up with Oct Cores (core i7) or can it only thread to 4 cores max....