Huge frame drops with laptop i7 4700mq, gtx 780m

I think setting it under VRAM limit will not cause any drops. Texture streaming budget saves textures in VRAM in order to reduce possible buffers. But some say keeping it at 2GB gives the best FPS. I can't go over 2GB so I can't give you my personal experience, just giving info within my knowledge. He will get no harm from trying. You may be right though. 🙂