Implementing something like UHD cache would be great but I think it should be done with the GPU in mind even if it means couple of years for it to be done… it makes everything so much more complicated to implement but doesn’t cause inconsistency. Cycles is more GPU than CPU oriented and cache would be a big step comparable to denoiser.
Are you sure? I think CPUs got a much bigger boost in the past 1 year than GPUs.
It was true from like 2012-2017 when Intel was kind of sitting on the throne and getting fat.
But recently you must have noticed that AMD pushed the limits and suddenly the race is on.