difficulties with my graphics card

[DarkRelicCry]

I'm having trouble with my graphics card it has 4GB of VRAM but when I start up any game it only uses 3.1GB and my BIOS won't let me allocate any RAM to it either...
GPU: XFX RADEON R7 250 4GB video card
motherboard: ASROCK FM2A78M PRO3+ Micro ATX FM2+

 

[BigBadBeef]

The graphics card will always use ONLY what it needs, considering how powerful this card is natively, you practically threw away money by buying the 4GB version instead of 2GB.