pavandsp

inconsistence execution time of the same kernel

Discussion created by pavandsp on Mar 11, 2010
Latest reply on Apr 15, 2010 by genaganna

Hi

I am getting the execution timings of the same kernel with different values like .25.7 msec,

31.4 msec,31.09 msec,28.11msec,30.7msec,27.8msec.

Why is this deviations..is this because of cache or some thing else.

I am doing below calc for timing,

clGetEventProfilingInfo(events[0],CL_PROFILING_COMMAND_START,sizeof(cl_ulong),&startTime,&length);
clGetEventProfilingInfo(events[0],CL_PROFILING_COMMAND_END,sizeof(cl_ulong),&endTime,&length);
cl_ulong elapsedTime = endTime-startTime;

 

Outcomes