Dell Latitude E6420 VRAM

So I have a Dell Latitude E6420 with the following specs :
16 GB RAM

i7 2720QM @2.2-3 GHz

Nvidia Quadro NVS 4200m

According to Nvidia control panel, I have a total of 2.5 GB of graphics memory / video memory (vram).

My question is, is it possible to somehow modify the amount of dedicated memory as there's only .5 gb of dedicated vram which cannot run games. Although some benchmarks show it can run some graphical games like Grand Theft Auto V at 53 fps, I want to know how to increase the vram as they have done these benchmarks with 1 gb of Vram which I cant even reach. Im aiming to atleast go for 2 GB if I could and then overclock the card a bit.
Thanks.