Intel Data Alignment

• SSE2 16 Byte
• AVX 32 Bytes
• Xeon Phi 64 Bytes

Alignment increases the efficiency of data loads and stores to and from the processor. When targeting the Intel® Supplemental Streaming Extensions 2 (Intel® SSE 2) platforms, use 16-byte alignment that facilitates the use of SSE-aligned load instructions. When targeting the Intel® Advanced Vector Extensions (Intel® AVX) instruction set, try to align data on a 32-byte boundary. (See Improving Performance by Aligning Data.) For Intel® Xeon Phi™ coprocessors, memory movement is optimal on 64-byte boundaries. (See Data Alignment to Assist Vectorization.)


https://software.intel.com/en-us/articles/explicit-vector-programming-best-known-methods