Following-up to a previous utility script posting, the following one-liner from Tim Cera will also do the trick.
This script (and quite a few others) have been loaded up onto the Gridengine.info Wiki “Utilities” page:
http://wiki.gridengine.info/wiki/index.php/Utilities
#!/bin/sh
qstat -g c -l arch=lx24-amd64 -q all.q | awk 'NR > 2 {sum = sum + $4} END {print sum}'