What exactly does the Linpack Fortran n=100 benchmark time?
The Linpack benchmark measures the performance of two routines from the Linpack collection of software. These routines are DGEFA and DGESL (these are double-precision versions; SGEFA and SGESL are their single-precision counterparts). DGEFA performs the LU decomposition with partial pivoting, and DGESL uses that decomposition to solve the given system of linear equations. Most of the time is spent in DGEFA. Once the matrix has been decomposed, DGESL is used to find the solution; this process requires O(n2) floating-point operations, as opposed to the O(n3) floating-point operations of DGEFA. The results for this benchmark can be found in Table 1 second column under LINPACK Benchmark n = 100 of the Linpack Benchmark Report.
