marlonjohn, your not approaching the FG/GI process in a reasonable manner. You shouldn't want to use it for the sake of a long render. I try to avoid long render times as much as possible. But if you must then---- really heavy scenes will increase render times quite a bit. Any high setting will increase a render time. The down side is that an exaggerated setting may cause unnexpected results or a bad quality render. I suggest learning the application better, then compare results with your old PC. Just my 2 cents mate.