[galaxy-dev] How are jobs counted in multi-threaded tools?

Hi all, I'm using 'user_job_limit = 8' and I will like to know if jobs for multi-threaded tools are counted based on some kind of multiple. I see for example a user can only run 2 ncbi_blast_plus jobs with my current configuration. Is this because the default numbers of threads for these jobs is 4? What happen if I modify the xml file and change the numbers of threads? Thanks, Carlos