BLAS library is the most basic math library in high performance computing. Its performance has a great impact on the performance of supercomputers. With the multi-core technology development, BLAS’ multi-core parallel performance has become more important than single-core performance associated with architecture. The experiment takes X86 multi-core processors like Xeon, Opteron series as platform for example, which are popular in HPC. It fully tests GotoBLAS, Atlas, MKL and ACML BLAS libraries of all 1,2,3-level functions, and covers different scales and multi-core parallel aspect. BLAS source code, material and papers, test results are used to analyze the way of BASL optimization and parallelism, and which platform they are suitable for. Then we will provide some useful suggestions for the use of BLAS, BLAS optimization method or even the development of high-performance CPUs. It was found that compared with a logically powerful and complex CPU, a CPU which has larger and better caches, wider memory bandwidth, smaller memory latency, higher core frequency can often obtain better performance in HPC applications. At the same time, the condition of X86 platform is also a good example for other architectures.