How to measure GPU performance

Hello,

I want to measure the performance of the GPU in NVIDIA’s GeForce 9400 GT

The steps in the host code are:

clSetKernelArg

clCreateCommandQueue

*start measure
clEnqueueNDRangeKernel

clEnqueueReadBuffer
*end measure

In order to compare I did the same calucation on the host without GPU.
It seems that even when the kernel does nothing, the GPU works 5 times faster than the host.

This does not make sense. It should work much faster. The NVIDIA has 16 cores each running at 1.4GHz. The host is Core2Duo running at 3GHz.

What is wrong in my measurment ?

Thanks,
Zvika

If the kernel does nothing you are only measuring the latency associated with the launching. This is not a proper comparison. I would recommend real problem comparisons.