Using CorePure64 you'll certainly have more ram available as compared to windows, but you would probably need to compile an Nvidia driver locally to access the vram.
As an example, booting my old intel laptop with 16gb ram and loading graphics-KERNEL, Xorg-7.7-3d, flwm, aterm, wbar, beaver and emelfm - after starting the gui and opening aterm, beaver and emelfm, "free" shows 15,803,744 bytes available.