[TheCrimsomBlade]

Thanks again and Robert & ILander are both right
you can configure them so one render the top and
the other the bottom or they can work as one card
and combine Ram to work together. it all depends on
the card manfacturer and the chip set on the card'

Thanks for the Link Felix you can get a complete explanation of both set ups and these combinations are more complex than I ever thought.

THANKS AGAIN GUYS
TCB