@lvl1201 said:
My money is the pc is running out of ram.
How much ram do you have?
If you have more than 4gb then i would suggest to do the LAA thingie (large addres aware).
You can download it from here. (http://www.techpowerup.com/forums/showthread.php?t=112556)
You can try too "cook" your light engines (IR LC or QM) for separated.
30 minutes is NOT that much time.
I used to render on a E8400, final renders took up to 3 hrs.
Hey Thanks! will check that out.