I have the graphics card above and I don't know how to increase the Dedicated Video Memory, when I go into my BIOS there isn't an option where I could possibly change it.
In most cases, the computer manufacturer has already configured the system to use the maximum amount of graphics memory that is possible for your particular computer model. Sometimes you can change these values through BIOS level.
Check with your computer manufacturer if there are tips on increasing the amount of graphics memory for your computer model.
If you are interested in additional information see graphics memory frequently asked questions: