I think the maximum amount you can use is 512 Mb. This is a limitation of all PC BIOSes that did not use the logical block addressing. On various actual PC machines, various BIOS updates raised this limit initially to 2 gb, then 8 then 36 and so on... but that's just symbolic of how the whole PC world works. You can't update your GG's BIOS so you will be stuck with 512.
