Very cool. Everything just looks so good

I don't get how you can have that many units in a battle, is it really playable like that? what settings are you using?
my settings:
1280x1024, 2xAA, bump-mapping, pixel shaders, directx 9 shaders, texture detail 100.
and my pc:
AMD Athlon 64 3500+
1 GB ram
Radeon 1900gt
and my pc can't handle battlesize 76; the screen goes black for like 1-2 sec sometimes and it's not very smooth when many units are on the screen at once.
Btw. are the battlefields enlarged to better suit big battles?