I should learn to post after the coffee infusion begins... the -j switch is for parallel makes (which I was in the middle of when I wrote the message). The -a option is correct. On Fri, 7 Mar 2003, ben wrote: > Joseph Landman wrote: > > > Possibly on an SMP, and that would be nice to see on this platform. > > Unlikely on HT. For BLAST however, the Athlon does nicely, and the -j 2 > > switch gives you 50-90% additional performance (search and algorithm > > dependent) from what I have tried myself on non-pathological cases. > > > > Hi , > I ' m afraid I didn' t understand .... is -j 2 parameter the one to make > blast aware of the dual smp aystem ? I' m using ncbi blast on a 2-P3 and I > thought it was -a 2 .. I' m asking because , after few testing with yeast db > I don' t see a big difference in running blast with 1 or 2 cpu ; maybe I set > the wrong parameter ? Shoud I also tell that I' m using Depends upon your problem, the machine, and a few other factors. BLAST is memory latency sensitive, and if your memory pipe is not large enough, that can become a factor as well. There are possible issues that can cause BLAST to not scale well using the -a switch. > blast with > 1 processor with some configs during the compilation ... > I think I didn't see anything about this > thanks in advance