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Transfering data between RAM and device memory

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• Host memory (= RAM) and device memory
  • Very important fact:

    Host memory (= RAM) and device memory are separate memories Variables stored in the host memory (RAM) are only accessible by CPU code Variables stored in the device memory are only accessible by GPU code

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• CUDA C-host functions used to transfer data between host memory (RAM) and device memory
  • Transfering data from host memory (RAM) to device memory:

    cudaMemcpy( devPtr, ramPtr, nBytes, cudaMemcpyHostToDevice ); Input: