If I'm not wrong, Age of Empires is not really demanding. I mean, it needs a 1.4 GHz single core, 256 MB of RAM and a 64MB video card. Test it with 3D Mark 06/Vantage and see what load you get.
What do you mean load? I cant get my 3D Mark score coz I can't currently get access to the internet (my wireless card wont install the drivers properly)
As you say I should be able to run AOE 3 max settings, but when I used the Nvidia monitor and turned on logging it said I only get a max of 50%