Hyper-memory = the video chip does not have dedicated video RAM. Video RAM is much faster that standard system RAM, so there are two points to remember.
1) Slower system RAM means less performance for the video subsystem.
2) Subtract the amount of video RAM from your total system RAM, as that RAM will no longer be available to run programs. i.e. If the video card is using 128MB of RAM, and your computer has 512MB of RAM, then your computer only really has 384MB of *useable* RAM.