my 1.2 duron with a volcano 6cu+ ran about 44-46 under 100% cpu usage. Now with a SVC gc68, that has been lapped and using Artic Alumina, I'm running at 39-41 under full load.
Both of these are withouth the cover on my comp. The 6cu+ was too loud to run without the cover most of the time, that's why I got the gc68. better cooling and much much quieter.