On Wed, 22 Dec 2010, Yongjun Chen wrote: > Satish, > > I have reconfigured the PETSC with ?download-mpich=1 and > ?with-device=ch3:sock. The results show that the speed up can now remain > increasing when computing cores increase from 1 to 16. However, the maximum > speed up is still only around 6.0 with 16 cores. The new log files can be > found in the attachment.
Perhaps this was mentioned eariler. Performance doesn't scale with number of cores. [its depends on both scalable compute unites -aka cores, as well as scalable memory modules] When the hardware is not designed to provide scalable performance - expecting it is wrong. The goal should be to extract max performance out of a given piece of hardware - not scalable performance. Wrt with-device=ch3:sock - it might not be the best performer for shared memory Try the default 'device=ch3:nemsis' Satish
