hairong Kuang wrote:
1. NNBench sets the block size to be 1. Althouth it generates a file with only 1 byte, but the file's checksum file has 16 bytes (12 bytes header plus 4 bytes checksums). Without the checksum file, only 1 block needs to be generated. With the checksum file, 17 blocks need to be generated. So the overhead of generating a checksum file is huge in this special case.
So to make this benchmark more representative of real performance with lots of small files, we should change the block size to 16 or greater. While small files may be typical, a blocksize of 1 is not. Since the benchmark only writes one byte per file, a tiny block size doesn't really need to be set at all for this benchmark.
Doug
