rsrsrs said he sometimes has to import a lot of content from AutoCad and ungrouped objects. There's a fair bit of graphical grunt taken up by the GPU, freeing the CPU. AutoCad (if used on the same machine) will perform better with a Quadro as well, they're even recommended in the specs from AutoDesk.

Graphics software typically like an abundance of RAM and GPU grunt, I presume Xara would be no different if you're pushing a lot of objects in one document.