Indeed! Marathon was written especially to take advantage of that chip. Gotta get your game on...
http://marathon.bungie.org/story/eWorldtrans1edited.html
Peace,
Drew
http://marathon.bungie.org/story/eWorldtrans1edited.html
But on a 6400, it's probably smarter to disable the 630 acceleration as the PowerPC 603e chip can easily handle any quality settings Marathon 1 throws at it.
Peace,
Drew