Someone from Planetside will say something here shortly probably ,
but if you ask me until they implement multhreading in the preview
or-and some GPU accelerating(do not count on it) etc.
you would be better to use a small render with low settings (the quick render camera node for example
)
especially with the power you have under your fingers it would be much accurate and faster too.
I certainly would use it if i had a computer like yours.
In fact i use crop renders with low setting more and more instead of the preview .
It is more accurate this way.
Sometimes i think instead of the preview window we have now
maybe Planetside should put the low render camera window direct there and should do the rendering automatic anyway