Basically, newer = better. So in general, a Barton is better than a Tbred, which is better than a Palimino, etc. The technical aspects, again in general - the Barton has 512K L2 cache and a FSB of 333, whereas the Tbred only has 256K and a FSB of 266. The Palimino was .18 micron, and the Tbred was .13 micron (Barton is .13 too).