I did some testing and seems that my low performance is caused by drivers or some incompatibility.
In a patrol using sh3, with a convoy at night, when the ships use the search lights the framerates dropped below a tolerable level using the external camera , a severe slowdown, while with my old 6600 i donīt have any problem in sh3.
i will try catalist 8.4 and see how it performs.
iīm now with 8.6