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Multi-core CPU licencing policy changes

The licencing policy for parallel processing is changed with FEKO Suite 5.4 to count CPUs, rather than cores. A sequential licence can now simulate in parallel on all cores of a single CPU. A parallel licence can simulate in parallel on all the cores of the number of CPUs that it is valid for.

Multi-core CPU licencing policy changes

Dual CPU Core Chip

In the past to make more powerful processors, the chip industry relied on shrinking a single processor and increasing its clock speed.  Technology limits (power consump­tion and heat) prevent this further.

The solution to this problem was to put more than one processor on the same chip and run them at moderate speeds.  Multi-core CPUs were born.  Today dual- and quad-core CPUs are standard, but CPUs with hundreds of cores are expected to appear within the next 10 years.

EMSS has taken the initiative to change the FEKO li­cence policy and licence management so that a sequen­tial licence allows using all cores of a single CPU while for parallel licences only the number of CPUs count (not the actual number of parallel processes then run on the individual cores).  This change will come into effect with the FEKO Suite 5.4 release end of July 2008.

To illustrate the difference:

In the old scheme sequential / parallel licences were de­fined with respect to the number of processes, i.e.
  • sequential  =  one process only
  • p-parallel    =  maximum of p parallel processes

 

In the new implementation from FEKO Suite 5.4 onwards, the definitions are:
  • sequential  =  1 CPU (with all its cores), i.e. a parallel run is supported using nc processes if nc is the number of cores that the CPU has.
  • p-parallel    =  nc*p parallel processes are supported [1].

Two examples to illustrate these changes shall be considered:

 

Notebook clipart

Example 1:

Notebook computer with a dual-core CPU.  To use the full computing power, in the past a 2-process parallel FEKO licence was required.  Now in Suite 5.4, a sequential licence is sufficient (as there is only one CPU involved).  This sequential licence then allows a parallel 2-proc­ess run.

 

Network clipart

Example 2:

Cluster with 6 nodes, each node having two quad-core CPUs (i.e. in total then 6 x 2 x 4 = 48 cores).  To use the full cluster, in the past a 48-process parallel FEKO licence was re­quired.  Now in Suite 5.4, only a parallel 12-CPU licence is sufficient (as there are 12 CPUs involved).  This parallel 12-CPU licence then allows a parallel 48-process run.

 

Note:

No changes in the launching mechanism were made, however, if users with a se­quential licence start just a 1-process job (i.e. sequential run) on a multi-core ma­chine, then FEKO detects this and gives a note that better performance can be achieved by running a nc-parallel job and that this can be done with the available sequen­tial licence). 

In case of questions, please feel free to contact your regional FEKO distributor or the EMSS FEKO Sales team.

 

[1]  Simplified presentation here, in reality more complex algorithm used which also works in cluster environments where CPUs are used with different numbers of cores.