Yep, I see it as latency vs throughput optimisation, particularly wrt memory subsystem. What I was pointing out is, x86 is not well suited to GPU execution; Int

Yep, I see it as latency vs throughput optimisation, particularly wrt memory subsystem. What I was pointing out is, x86 is not well suited to GPU execution; Intel tried that with Larrabee. Moreover, in the latest generation Nvidia chips you have 72-96mb L2 cache and 2.5ghz+ clock speed, so it's remarkably capable per-thread. At some point, and I think 256 cores might be the ballpark, you're committing to using so many threads that you're probably mostly interested in high throughput. (I'm writing commercial path tracers so my bias is obvious!)