Posted by Arnold on Jan 25, 2017; 8:36pm
URL: https://forum.jogamp.org/Enigmatic-benchmark-results-tp4037603.html

Hi,

I started programming in openCL. My system is a core i7-920 12 GB and an NVidia GTX 1060 with 6GB. I started experimenting with the HelloWorld example and have it run 3 kernels: a+v=c, a*b=c and a/b=-c. Each vector contains 20mln elements just to make the benchmark results meaningful.

I got the following results (in ms, mileage may vary):

+   159   159
*   152   179
/    156   153

Well, there go my dreams of having built a small supercomputer, the graphics card is about as fast as the CPU. But it gets worse: I built a small benchmark subroutine that computes a/b=c 20 mln times and it does so in 78ms!

Results are changing when I throw in trigoniometric functions like sin(a)/cos(b)=c (the benchmark takes 4 times as much computation time). Is this normal? I hope not because I find it really somewhat discouraging. Note that I only time the queue.put... function. I can post the code when desired but maybe one of you cracks knows the answer beforehand.

One of the questions I have is about the number of processors. This is 8 for the i7-920 which is ok. But the GTX 1060 has just 10, while the specs tell me it has 1280 stream processors. Does anyone how that relates?

Thanks very much for your time.