I recently switched from Mcafee to Avast as suggested by Bob Bone.  Although I'm only a few days into the experiment, I have already noticed a hefty improvement in my CPU's performance.  I actually came out of a 4 hour session with a clean bill of health compliments of LatencyMon!  I hadn't had a crash free session for months under mcafees reign of terror.  Of course, this is less an indicator of Avast's performance than it is confirmation of Mcafee having been the root of all evil here and abroad, nonetheless; I give credit where credit is due.  Thanks Bob!
 
By the way, it is completely possible that I was the problem and not mcafee.  No offense intended to anyone that might swear by the mcafee product.  My relationship with mcafee is, well.... complicated.