Configuring Parameters
The most significant parameters in
HPL.dat
are
P, Q, NB
, and
N
. Specify them as follows:
 PandQ the number of rows and columns in the process grid, respectively.P*Qmust be the number of MPI processes that HPL is using.ChooseP≤Q.
 NB the block size of the data distribution.The table below shows recommended values ofNBfor different Intel® processors:ProcessorNBIntel® Xeon® Processor X56*/E56*/E7*/E7*/X7* (codenamed Nehalem or Westmere)256Intel Xeon Processor E26*/E26* v2 (codenamed Sandy Bridge or Ivy Bridge)256Intel Xeon Processor E26* v3/E26* v4 (codenamed Haswell or Broadwell)192Intel® Core™ i3/i5/i76* Processor (codenamed Skylake Client)192Intel® Xeon Phi™ Processor 72* (codenamed Knights Landing)336Intel Xeon Processor supporting Intel® Advanced Vector Extensions 512 (Intel® AVX512) instructions (codenamed Skylake Server)384
 N the problem size:
 For homogeneous runs, chooseNdivisible byNB*LCM(P,Q), whereLCMis the least common multiple of the two numbers.
 For heterogeneous runs, see Heterogeneous Support in the Intel® Distribution for LINPACK* Benchmark for how to chooseN.
IncreasingNusually increases performance, but the size ofNis bounded by memory. In general, you can compute the memory required to store the matrix (which does not count internal buffers) as 8*N*N/(P*Q) bytes, whereNis the problem size andPandQare the process grids inHPL.dat. A general rule of thumb is to choose a problem size that fills 80% of memory.
Product and Performance Information


Performance varies by use, configuration and other factors. Learn more at
www.Intel.com/PerformanceIndex.
Notice revision #20201201
