Hello

I'm from indonesia.
My comp
- amd tinity A8-5600K 3.6GHz FM2
- Asrock A55 DGS R2.0
- Ram 8Gb dual channel
- Bios version 1.40
- Graphics onboard

from spesifications Asrock A55 DGS R2.0, Graphics Max. shared memory 2GB.
How to change from default 512Mb to 2GB ? i can't find in bios to change it.

Thank you