Quote - Mine is a GEForce GT 540M, 96 Cuda cores...it works  (though I did need the latest NVidia driver)!  Still watching videos, so I am not sure if this is like lux (i.e it can go on forever)?

For mine, at 2 minutes I had 700/16000 s/px, now at 1200 and it looks darn good!  (spaceships scene)

As far as I know any unbiased render will go on and on until you tell it to stop ;).