Dec 21, 2016

Going further, power for power on the current generation, for SGEMM, i'd expect GPUs to beat CPUs by maybe 5x (6700k has a theoretical 512 gflops at 91W, while xeons can come a bit shy of 1.5 tflops at 145w)

Which is still pretty major, but nowhere near the wild claims that used to be common in academic papers. It's outdated, but [1] is still pretty good reading.

[1] http://sbel.wisc.edu/Courses/ME964/Literature/LeeDebunkGPU20...

Sep 04, 2016

> Is this a typical performance profile for doing ray tracing in OpenGL? I expected tens of times faster than a CPU on commodity hardware.

SIMD instructions on modern CPUs are getting really good, within the ballpark of GPU speed in some cases. Here's the classic paper [1] on this, and the results have gotten even better since then with AVX2, etc.

[1]: http://sbel.wisc.edu/Courses/ME964/Literature/LeeDebunkGPU20...

Apr 10, 2016

"Debunking the 100X GPU vs. CPU Myth: An Evaluation of Throughput Computing on CPU and GPU" is a good paper on this; obviously has an agenda, but rings true in my experience.

http://sbel.wisc.edu/Courses/ME964/Literature/LeeDebunkGPU20...