Quote - In this regard I like how LuxRender is using the GPU: to accelerate the floating point calculations for raytraing.

This approach is not as aggressive as what SLG does but it doesn't run into GPU memory limitations, the RAM used is the one available on your motherboard. Over time it will be refined to make it more efficient and I believe that at that point we will have the best of both worlds.

Yes, this is the point I picked up on, on the LuxRender site...

I've got a 2GB GPU... so yeah, significantly less RAM for the SLG or Cycles type approach, than the 16GB I have on my mainboard... which itself isn't that much these days (although max for an imac).