I have a brand new computer with quad processors and Desume was going slow.  I found this forum, and when I went to set affinity I had 8 (marked 0-7) CPUS. I turned off all the odd numbered ones, so 1, 3, 5, and 7, and how Desume is going super fast (over 100 FPS).  That tripled my speed.  This is such a weird fix that I know I wouldn't have figured it out on my own and I'm sure others are in the same situation.  Thanks for the help!!!