John Carmack on id Tech 6, Ray Tracing, Consoles, Physics and more on PC Perspective is a Q&A with the id Software cofounder and technical director. The conversation focuses on very technical details about graphics engine development, sure to be a help to anyone writing a doctoral thesis on the advantages of sparse voxel octree-based technology. He also admits "the uncomfortable truth" that consoles are the driving force behind game development, so "it’s difficult to set things up so that you can do much to leverage the really extreme high end desktop settings." He also talks about the pros and cons of multi-CPU and multi-GPU systems, making it clear that problems taking advantage of these technologies are due to bigger issues than simple growing pains:

Whether it makes sense for gaming to have these thousand dollar graphics cards is quite debatable but it’s really good for developers; to be able to target something high end that’s going to come out three years from now by being able to pay more money today for 2x more power. Certainly the whole high end simulation business has benefited a lot from commoditization of scalable graphics.

Although on the down side it was clear that years back when everything was going in a fairly simple algorithmic approach as far as graphics engines where you just rendered to your frame buffer, it was easy for them to go ahead and chunk that frame buffer up into an arbitrary number of pieces. But now there is much more tight coupling between the graphics render and the GPUs where there are all sorts of feedbacks, rendering to sub buffers, going back and forth, getting dependent conditional query results, and it makes it a lot harder to just chunk the problem up like that. But that’s the whole tale of multi-processing since the very beginning; we’re fighting that with multiple CPUs. It’s the primary issue with advancing performance in computing.