No harm in trying I suppose, as a few MB here or there isn't going to drastically alter things too much. I'd definitely try raising the graphics RAM to see what it did for overall system performance, or just out of curiosity even!
If you know where the setting is in the BIOS, make the change & save it before exiting. And, as it's easily reversible, you can always go back to the previous setting, or try another one. G