Since a matrix can be seen as a linear map , the product of two matrices can be seen as the composition of two linear maps:
One cool thing about linear functions is that we can easily pre-calculate this product only once to obtain a new matrix, and so we don't have to do both multiplications separately each time.
No 2x2 examples please. I'm talking about large matrices that would be used in supercomputers.
TODO application.
TODO speedup over algorithm for general matrices.
www.studentclustercompetition.us/ comments:
The HPCG benchmark uses a preconditioned conjugate gradient (PCG) algorithm to measure the performance of HPC platforms with respect to frequently observed but challenging patterns of computing, communication, and memory access. While HPL provides an optimistic performance target for applications, HPCG can be considered as a lower bound on performance. Many of the top 500 supercomputers also provide their HPCG performance as a reference.
The terminology GEMM is present on BLAS, and has stuck pretty much.