- Sep 10, 2012
I think this is a valid point, but I don't see a scenario in the future where we go back to GPUs with purely fixed function units like they were back in the early-2000s. I'm far from an expert on this, but there might be more advanced RT algorithms or methods that get developed in the future that results in the RT unit becoming more flexible or programmable in nature, especially if there comes a point in time where we can cast so many rays per frame that a denoising step isn't necessary (i.e. FPS is more correlated to the efficacy of the RT units themselves), but that would support the argument that we're going less fixed function, not more fixed function. If this is true, then what has happened is that the RT unit has supplanted the programmable shader unit as the standard building block or execution unit of the GPU, but it doesn't make the execution unit any more fixed function.Pardon the interruption but, if the talk by Bill Dally, chief scientist at Nvidia, is anything to go by, I don't think Nvidia will move away from fixed function units to handle raytracing anytime soon, nor AMD BTW.
He makes a compelling case for them as he argues that that type of unit is the way to continue to improve performance per watt as Dennard scaling is no more. I think AMD is aware of this and they will introduce more of those types of units on RDNA3 as future nodes would allow them to dedicate more transistors to them and further improve on this metric.
Not that it matters, but I believe AMD did the right thing when they decided to go the IC route so as to keep the data on chip and not go to memory as much. In the future they'll have to introduce specialised hardware judiciously if they intend to keep up with the trend they currently have.
EDIT: Rephrased for clarity.