What exactly is a "CUDA core"?

Is that not the number of processors in a given Nvidia cpu??... 

Do you have a better answer? ATI cards have processors...

http://en.wikipedia.org/wiki/CUDA
http://www.nvidia.com/object/what_is_cuda_new.html

It's all the same thing. Stream processor, Cuda core, no real difference. Its the thing the does the job of the old pixel and vertex shaders. There ARE differences between them which is why AMD has 1,000+ on their cards while Nvidia has 512. But they do the same job.

Is that better or are you looking for something else?

How much do the Cuda cores or Stream Processors make a difference from:

336 Processor Cores
384 Processor Cores
448 Processor Cores

or are these cards totally different?

http://www.newegg.com/Product/Productcompare.aspx?Submi...

Sorry I'll start a new thread.
http://www.tomshardware.com/forum/345961-33-stream-proc...