don't know... well will see that in two weeks min...
on a side note, that's more than a r9 290x  

edit: doesn't make much sense... you should get at least twice the hashrate of the 750ti (256bit mem bus against 128bit)

Try to check if you are in boost mode (just in case) and may-be try to increase the memory clock

edit 2: what is this compute 5.2 they are talking about on the blog, I can't even find a ref. on nvidia site....)