Inspiron 17R 5720 - Intel HD 4000 - Dont Limit Me Dell

Why am I limited with the Intel HD 4000 Graphics card? I have 8gb of Ram and the HD4000 is capable of using up to 2gb shared memory of that 8gb and it only seems to ever use up to 160MB!!! of ram.......... If it was up to me I would let it use a minimum of 1.5gb constantly and still have 6.5GB of Ram dedicated to my computer. The fact that it only dedicates 160mb of ram (While running a game) to the video card is ridiculous. At least let me have the option of setting the minimum. Biggest downfall of my laptop and it makes me never want to buy Dell again because the only other fix besides an UNLOCKED BIOS would be to get a new (Non Dell) laptop. Please shed some hope on my situation and tell me that the Bios settings for the Intel Integrated HD 4000 Graphics card can be modified.