Could you please specify your graphics card? if you click on the start button and type "Device manager" into the search bar you can find the graphics card on Display adapters. Also, your work is amazing, did you study biology and draw when creating your characters? Im gonna be studying muscles for my characters but i dont know if thats enough, you been doing this for a long time?
but you have to know it really depends on with what program you are working with and what render engine you are using for the end renders.. for example, if you just want to sculpt, then a mesh can go up to a couple of million polygons.. but if you want to animate it too then having so many polygons going on at your model isnt really the smartest way to work.. so if you want to make animation or models for a game engines then you have to keep things a lot simpler and low poly.. but keep in mind, the higher the poly count the higher the resources are needed to keep you pc from running that mesh
as for the render engine there are two kinds of render engine we have.. simply said the biggest different is when the calculation is been done over the cpu or the gpu.. when working with a gpu render engine then obliviously a faster and high end graphics card is required.. as opposite to working with a cpu render engine were a faster processor and more cores are required..
I spent a long time researching rendering so i understand what your talking about, im planning on getting the GTX 780 so yea, high end. As for the polygons and animation dont you animate by rigging your character? Also, how long have you been doing 3d modeling? and when creating your characters did you draw them yourself? Im gonna be studying alittle biology mostly muscles and joints, is that enough? from the animations i've seen yours are photorealistic so you seem experienced, so i would like to know what you did to achieve the models you have and what you studied to get the animations realistic.
The texture is awesome, and the general concept too. I really liked it.
But, if you excuse my thoughts, I think the front of this "speeder" should be less flat. The bike looks fast, so the front should allow the air to flow more efficiently. If you remember the airplanes we have, and even the motorcicles, they all "cut the wind".