Fairly good, hopefully your card won't thermal/voltage/boost throttle itself to much in your small case.
I did a TimeSpy bench run myself just now.
http://www.3dmark.com/3dm/15874541?
And alittle comparing
http://www.3dmark.com/compare/spy/685688/spy/686026#
EDIT:
I wanted to test my card running it stock in TimeSpy, but my card keeps crashing the benchmark, so i don't know what is going on, but it works when it is overclock strangely enough...
Yet another nail the coffin for the 1070 FTW ...
But i think TimeSpy is a GPU power whore as it makes the card use my power than it can deliver with default settings, so i need to bump up the voltage for it to work.