Simple parallel benchmark for Nonmem 7.2 with large Bayes problem

Here some quick-and-dirty results of my first benchmark with parallel processing in NONMEM 7.2 Running Win7, 64 bit, intel i7, with 4 CPU (and 4 hyperthreading cores). One computer only. Using file message passing. Could not get mpi to work in this configuration. call nmfe72 mtl_KPreM2Pre_T2L2_.ctl -parafile=fpiwini8.pnm [nodes]= (1 or 4 or 8) 10 iterations of a very large Bayes problem (which should not profit from multiple cores, according to the manual) nodes time 1 45 s 4 25 s 8 40 s So about a factor of 2 between 1 and 4 cores. It is not surprising that 8 gives worse values because these are no real CPUs. More surprising is the fact that with 8 "CPU", I have 100 load on all of them (huh?), while with 4 CPUs, I have the expected 50%. Dieter