I was looking at that AMD 64 CPu with the newcastle thingy,

Does that really run at 2.4Ghz compared to the 2.2 AMD Retail one? Or does it run at 2.2Ghz and thats just a gimmick?

also I aksed this realy but, will the 1MB cache vs the 512Kb cache make a big difference in performance?

and should I go for the 2.4Ghz 512Kb cache Cpu
the 2.2Ghz 1MB cache cpu?

If they're both 3400+ chips they'll both have equivalent performance.

then why does one have 512Kb cache and operates at 2.4Ghz and another has a 1Mb cache and operates at 2.2Ghz? I don't think thats operating the same

The one's balancing out the other to give a chip that performs at an equivalent level. The number in the product name, after all, is a "Performance Rating".

Similar things happened with Athlon XP processors. Some models had minor changes to architecture and clockspeed involved. There were a couple of versions of most performance rating chips, and there were 3 distinct versions of some of them ;)