irqbalance is a Linux daemon that distributes interrupts over the
processors and cores you have in your computer system.  The design
goal of irqbalance is to find a balance between power savings and
optimal performance. To a large degree, the work irqbalance does is
invisible to you; if irqbalance performs its job correctly, nobody
will ever notice it's there or want to turn it off.

It is recommended to run irqbalance from the system boot-scripts. For
example, add the following lines to /etc/rc.d/rc.local:
if [ -x /usr/sbin/irqbalance ]; then
  /usr/sbin/irqbalance
fi

Options that you can pass to the command are described in the man page.