thats a good idle, what about a full load? try running prime 95 to stress it
http://www.mersenne.org/
if it gets HOT fast stop the workers. if it runs for 20 minutes with temps not going over 65 your good. under 60 is excellent. 70 or over could be a problem.
running on that resolution will be a larger load on your cpu with the gpu being able to put out more frames.