"Understanding" isn't so important. At the end of the results, there is a number labeled "GLOPS". It looks like this:

Code:

WR00L2C2        8192    16     1     1             327.60          1.119e+00

The first column expresses some of the options used in the options (HPL.dat) file. The next two columns express the size in dimensions. The last column -- the one you want -- is the number of Gigaflops measured for that run. It's in scientific notation, meaning:

Code:

1.119 x 10^(00)  = 1.119 GFlops

If the output were 3.42e-01, then you'd have:

Code:

3.42 x 10^(-01) = 0.342 GFlops = 342 MFlops

Do you understand now?

---------- Post updated at 10:02 AM ---------- Previous update was at 09:34 AM ----------

As to how to configure this to run on multiple nodes, you have to (1) configure HPL.dat to run on mxn processors, where m and n are close together; so if you have a cluster containing 12 cores, optimal is normally m=3 and n=4. That's not always the case, but it typically is. (2) You must configure your MPI environment so that it runs on that many processors. How you do #2 depends on your MPICH software and setup. If you have a batch system like PBS or SGE, that further complicates the matter, as you need to queue the job with that number of processors. Sometimes with queuing engines, you can't easily dictate which nodes the job will run on. So if you have 6 nodes each with 4 cores, it might not be possible to say "run this on 3 nodes using all cores on each one". (But normally it's possible to say "run it on 3 nodes using 1 core on each one".)