In modern motherboards BIOS, you can find the Above 4G Decoding checkbox, and now the Resizable Bar has appeared next to it. And the Resizable Bar was already well explained by AMD – the processor can directly communicate with the card through a couple of big steps, instead of a million tiny ones.
But what then is Above 4G Decoding and is it equal to Resizable Bar? No article on the internet explains the term precisely, but I will try to make the best explanation possible.