But the amount of RAM you can stick in a box is a hardware limitation, not a software one.
I have to disagree, mixture. I've several times come across a BIOS upgrade allowing increased overall memory capacity by introducing firmware support for higher capacity RAM modules. Obviously it won't increase the number of slots.
maxed-out, unless the BIOS upgrade release notes specifically state that support for larger memory modules is part of the update, then just doing it in hope is likely to be fruitless.
There's always a risk to updating the BIOS, but unless you've got a dodgy electricity supply it's minimal, providing you follow the instructions carefully.
SD