STREAM is a microbenchmark for measuring data memory system performance without any data reuse. It is designed to miss on caches and exercise the data prefetcher and speculative accesses. It uses double precision floating point (64 bit), but in most modern processors the memory access is the bottleneck. The four individual scores are copy, scale as in multiply by constant, add two numbers, and triad for multiply accumulate. For bandwidth, a byte read counts as one and a byte written counts as one resulting in a score that is double the bandwidth LMBench. Table 3-2 shows the measured bandwidth and the efficiency compared to theoretical wire rate. The wire rate used is the DDR MT/s rate times the width. To get overall maximum achieved throughput the command used is stream -M 16M -P 4-N 10, which means two parallel threads and 10 iterations.