AMD released a new batch of chips - socket 939 opterons, easily detected, all 1MB cache, including the new cheapest DC opteron 165, which is 1.8GHz , and 1 MB cache per core.
Being based on the latest core revision, they're proving to be great overclockers - so if you're jumping on the p3p or DC bandwagon soon, you may want to wait a couple weeks as reports come in.
here's a thread to where some are ocing the new chips
http://forums.pimprig.com/showthread.php?p=446310link to prices on newegg.note- $289 for the new low end DC.