There is currently an eighty dollar difference between the these two and I was wondering is anyone thought the .2ghz difference was worth 80 bucks. FYI dell optiplex 620, currently running P4 @ 3.6 HT. I use this machine for general purpose stuff, gaming (older games mostly) with occasional video encoding while I build my i7 920 monster. All my encoding software is multiprocessor aware.
IMO you will not see much of a improvement going from your P4 @3.6HT. The Pentium D family of processors are worthless IMO they are just two P4 chips on one die and are very inefficient. I would not even waist the money on one of those chips if it will allow it atleast go to a core 2 or a pentium dual core which are different then the pentium Ds.