I run shows in 2 universes off an i7 PC with SSD and have never had any issues. Some of my students do have i3s and even intel ATOMs and I find they tend to struggle a bit with 3d View. I personally have never had an issue.
The only time i notice any slowness is when loading large Sequential Lists. My sequential lists for shows can sometimes be up to 100Kb in size as I'm creating very large macros. FYI 100kb for a Sequential List is pretty massive. The software actually hangs for about 10 seconds when loading those lists.