Intel 660 3.6Ghz & 3.73Ghz Extreme Edition 64bit Pentium 4 Processor
 

"With Windows x64 Edition nearing its' full release date, Intel has released their 64bit capable 6XX and Extreme Edition line of processors to tackle the new 64bit challenge and the nice thing is if you own a Intel® 925XE Express or i915 based chipset motherboard, 64bit computing is only a processor and a BIOS flash upgrade away.

Let's see what the new line of Intel processors have to offer...."

http://www.tweaknews.net/reviews/intel64/