From: Sensei <sen...@gm...> - 2017-02-18 14:42:46
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> On Feb 17, 2017, at 8:05pm, Karl Rupp <ru...@iu...> wrote: > > Hi, > > I suspect that your timings include kernel compilation times. Please have a 'warmup' call of norm_1() outside your timing region. > > Which GPU do you have on your Macbook Pro? > > Best regards, > Karli Thanks Karl & Oswin, The GPU is an Intel HD Graphics 4000. What worries me is not only the warmup, but the copy phase. In release it can take a lot of time for a simple 1M items (169 seconds!). I suspect I should try to do everything on the GPU. Not only that, but this call: viennacl::vector<float> gpuv; gpuv.resize(size); is taking 6 times what it takes on the CPU. How can I avoid these overheads? I am quite new with OpenCL... Thank you! |