[Edi]

All you need to do is turn the battle detail to "Too High" and maximum grass on and I an guarantee that your new-fangled machine will choke to death on Dom3. Johan K wasn't kidding when he marked that setting as being too high, since it will draw every (separately animated) blade of grass for 10 km out, only you'd need a 10k x 8k resolution to see them...

Dom3 is single threaded, so you won't get multicore processing efficiency out of the new processor, but otherwise everything will run fine if you avoid the above mentioned ridiculous settings.