In case anyone was wondering, on the specific laptop i have acer v3-551g-x419, it is not possible to alter that 512mb vram limit in the bios. The motherboard doesn't support this so neither does the bios. I don't doubt that it can be done on other systems however. Even by modding the bios for this mobo it is not possible because the mobo is very basic, but maybe on a different mobo.