"Less than that. Most kits until pretty recently had only 1.5 GB usable for graphics"
http://beyond3d.com/showpost.php?p=1712366&postcount=111
"Phil is a developer, so I would say he speaks the truth."
http://beyond3d.com/showpost.php?p=1712622&postcount=67
Take with a grain of salt, of course.