I think you will find that the preview performance is controlled by the cpu rather than the gpu, and also it depends on the single thread performance of the processor. I've done a quick check by loading a scene with resource monitor running, and when I mover the camera around only one thread was heavily loaded, most of the rest being fairly idle, while the one core was running at it's max turbo boost frequency. So ReggieKowalski, it's probably your relatively slow processor that's causing jerkiness. So if preview speed is your priority I would suggest looking for a processor with the highest clock speed/turbo boost speed possibly within your budget.