Graphics performance

[ozconnect]

We have a need to display 3D walkthrus on a PDA and are concerned about performance.
Does anyone know if the Intel XScale based machines runing CE use the main cpu or a separate graphics chip to handle the display.

Is performance slower on the Toshiba running 640X400 because of the increased pixels to manipulate compared to the Ipaq at 320X200 with the same cpu chip?or is there a separate processor to handle the increased display resolution?