Is this B2D?  If so than yes, go into the b2d properties and set concurrent jobs to a number greater than 1. see the attached image.  It is recommended that you test adding concurrent sessions one at a time to see how this affects performance and usually running no more than 5 jobs max.

also here is a link for Backup Exec 2012 B2D Best Practices http://www.symantec.com/business/support/index?page=content&id=TECH164267