CPU utilization in cluster(method=agc)

It appears that vsearch is ignoring the # of processors set in mothur.

Using vsearch agc method for clustering, I am seeing the following (actual utilization is lower than 32, thankfully, likely due to disk IO):

Current files saved by mothur:

Current default directory saved by mothur: /usr/analysis/tools/mothur/

Current working directory: /gluster/scholzmb/AllSamples/data/temp/

Output File Names:

mothur > cluster(fasta=current, name=current, method=agc) Using stability.trim.contigs.good.good.unique.good.good.filter.precluster.pick.fasta as input file for the fasta parameter. Using stability.trim.contigs.good.good.unique.good.good.filter.precluster.pick.names as input file for the name parameter. You did not set a cutoff, using 0.03. vsearch v2.0.2_linux_x86_64, 378.5GB RAM, 32 cores https://github.com/torognes/vsearch

$ mothur -v
Linux 64Bit Version
Mothur version=1.38.1
Release Date=8/9/2016

Vsearch outputs the total number of processors available, regardless of the number set to be used in the parameters inputted.