Firstly don't expect much different of other 980m based machines. At this point I don't think the 8GB of VRAM is going to make a hill of beans as its just not being used. Some of these scores are expected, others a bit on the low side. How do you have NVIDIA control panel settings set up? This in itself can make a huge difference in benchmark scores.
Personally I don't pay much attention to those benches. I watch actual performance and tweak settings to suit my preferences. You can tweak it out to maximize 3D mark scores or to meet a happy medium of performance and quality. Fast is t worth a hoot if it looks like crap!
“Two things are infinite: the universe and human stupidity, I'm not sure about the former” ~ Albert Einstein