I think HiddenX's ones should be ok for your Rig (i.e reducing the pop-in without killing framerate too much). Perhaps raise the small values a bit if your PC can handle it ?

Mine i.e (I ended up setting even more extreme values increasing my mins and pushing medium and large values further) are more of a brute force approach and bring the framerate quite a bit (30 fps min) down on a core i7960 ATI 5870 (somewhat better than yours)… I just can't stand NPCs i.e popping into existanse a few "meters" away
(I also double the Roi value on G3 usually )