Ok, I just recently bought a 3800+ x2 cpu and so far very happy. I was just curious as to what difference a socket 939 opteron has over an x2. There is additional cache I believe, but other than that, they seem pretty similar.
opty's are better... lower voltage higher oc. I own a opteron 165 and its running @ 2.6ghz with 2mb of L2 cache stock voltage (1.3) and stock cooler (got the new 4 heat pipe cooler from newegg)
so far on air I had it @ 2.7ghz with 1.4 volts and now im running it @ 2.6 with stock voltage and prime95 stable for 24hrs