that why its pr 4000 and not pr 3800I would go for the 4000+, it's got a 1MB L2 Cache
well they are different cores, but like you said the only diff on the tech sheet is the cachethe only difference between those two cores are the cache. So technically both should have the same ability to OC, but it really depends from chip to chip.
since they've yet to make a 5000+ how will you know when you get thereit'll be cool, ill have an AMD Athlon 64 4000+ oc'd to HOPEFULLY a 5000+