CUDA Cluster - HPL Help

Hello everyone,

So I am currently taking part in an academic research project dealing with HPC. My team has constructed a cluster consisting of two nodes and the following spec:

Node (x2)
8-core AMD CPU
3 x GTX 660 Ti
2 x 8GB RAM

I have successfully acquired and built the HPL that Nvidia provides as part of their developer program, but I am facing some issues getting it to run correctly.

When I execute the following command:

mpiexec -np 6 -hostfile hostfile ./run_linpack

I get the first part of what you would normally see with the HPL:

TestingHPLinpack 2.0  --  High-Performance Linpack benchmark  --   September 10, 2008
Written by A. Petitet and R. Clint Whaley,  Innovative Computing Laboratory, UTK
Modified by Piotr Luszczek, Innovative Computing Laboratory, UTK
Modified by Julien Langou, University of Colorado Denver

An explanation of the input/output parameters follows:
T/V    : Wall time / encoded variant.
N      : The order of the coefficient matrix A.
NB     : The partitioning blocking factor.
P      : The number of process rows.
Q      : The number of process columns.
Time   : Time in seconds to solve the linear system.
Gflops : Rate of execution for solving the linear system.

The following parameter values will be used:

N      :   25000 
NB     :     768 
PMAP   : Row-major process mapping
P      :       2 
Q      :       2 
PFACT  :    Left 
NBMIN  :       2 
NDIV   :       2 
RFACT  :    Left 
BCAST  :   1ring 
DEPTH  :       1 
SWAP   : Spread-roll (long)
L1     : no-transposed form
U      : no-transposed form
EQUIL  : yes
ALIGN  : 8 double precision words


- The matrix A is randomly generated for each test.
- The following scaled residual check will be computed:
      ||Ax-b||_oo / ( eps * ( || x ||_oo * || A ||_oo + || b ||_oo ) * N )
- The relative machine precision (eps) is taken to be               1.110223e-16
- Computational tests pass if scaled residuals are less than                16.0

At this point, however, nothing new ever appears. Eventually I get a “Bad Pipe” error message, but I assume that is from my SSH session, and not the HPL.

I can verify that 6 instances of the xhpl executable are indeed running (three per node), and that they are consuming 100% of a CPU core each.

Here is my software stack:
Ubuntu Server 12.04.3
CUDA version 5.5
ACML 5.3.1
GCC 4.6.3
MPICH2 3.0.4 (I think that is the version)

Any information or help would be greatly appreciated! Please let me know if I can provide you with any additional information.



The number of MPI processes should equal the number of GPUs and this should equal PxQ. Looks like you have PxQ=2x2. I’d try changing the PxQ to either 2X3 or 3x2 in the HPL.dat.

Let me know if that works or not!