Currently, it seems there is no way to set a specific number of cores with the script run_discoSnp++.sh, and by default, it takes all available cores, independently of the number of input files. It could be improved in a future version with a new argument for such a setting.
For the moment, you can modify the script by yourself and add directly -nb-cores X (where X is the number of cores to be used) at the end of the following lines:
- line holding the "dbgh5" command
- line holding the "kissnp2" command
For instance, it would be (for 4 cores):
$DISCO_BUILD_PATH/ext/gatb-core/bin/dbgh5 -in ... ... ... -nb-cores 4
$DISCO_BUILD_PATH/tools/kissnp2/kissnp2 -in ... ... ... -nb-cores 4
I have not tested this but I think it should work.