-AMD FX 8370 8 core CPU @4.2Ghz
-GTX 550ti (upgrading soon to a GXT triple windforce 960 :D)
-12 GB of CL9 1600mhz system memory
A large mesh, well actually, even meshes of only moderate poly counts will lag a notable amount in edit mode. I’m very disappointed. I took this one mesh that was giving me this lag trouble in blender even just on some of the sub-parts of it, combined it all into one mesh, sent it to maya, and entered face mode and it ran just as smooth as it normally does. Same situation in 3DS, Modo, and C4D. All of the other programs ran perfectly smooth with this huge mesh in their respective wire-frame overlay face selection modes or what-have you.
Blender is a fault here. It does not handle the polys well at all in edit mode. I heard of some sort of viewport improvements were coming, perhaps they intend to sole this issue with that? I sure hope so, I can hardly bare editing larger poly meshes >:C