I have a small cluster of computers with uneven clock speed CPUs and currently I am running with "-np" == total number of cores. However, it appears as if the fastest computer has to wait for the slower ones to finish at the end (at least I believe so). The most recent process took 65 hours so I am interested in finding ways to optimise the process. Is it possible to, say, use a larger "-np" and then increase the thread number for the faster CPUs in the machine file to make the faster computers do more work so, ideally, they all finish about the same time? Will it finish off the first batch then start on the next batch? Or, will the faster computers just get more concurrent jobs, possibly slowing down the processing? eg, if the single CPU of PC_A has twice the clock rating to that of single CPU PC_B, and both has quad cores, then use -np=12 and then have the following in the machinefile: PC_A:8 PC_B:4 Perhaps this is something better addressed with job scheduling software like GridEngine? Reuti? Thanks, Ron -- *Ron Palmer*MSc MBA. Principal Geophysicist [email protected] <mailto:[email protected]> 0413 579 099 07 3103 4963