From: Sensei <sen...@gm...> - 2017-02-18 15:02:08
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> 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! > Sorry, I forgot the log for the twice-computed norm: Computing norm_1 on GPU Computing norm_1 on GPU 347 Computing norm_1 on GPU (again) Computing norm_1 on GPU 2 Computing norm_1 on CPU Computing norm_1 on CPU 0 As you can see, yes, the OpenCL compilation takes a lot of time, but still higher than the CPU (with cache and all, I know). |