AMD's latest roadmap calls for the arrival of 12-core Magny-Cours Opteron processors in the first quarter of next year, so it's about time we started seeing some samples out in the wild. XtremeSystems Forums member s7e9h3n has gotten hold of one, and he's poked, prodded, and posted screenshots aplenty.
Judging by the first CPU-Z screenshot, the sample has 12 cores, 12 threads, a 1.7GHz clock speed, 6MB of L2 cache (512KB per core), 10MB of L3, and a 1.04V core voltage. s7e9h3n actually seems to be running two of these CPUs in a sample Socket G34 motherboard packed with 8GB of 1,333MHz DDR3 memory.
The system successfully ran wPrime as well as a memory bandwidth test, in which it reached almost 42GB/s. (Socket G34 systems are supposed to have four memory channels, so if my math is right, 42GB/s is pretty much the theoretical maximum with 1,333MHz DDR3.)
s7e9h3n also tried overclocking, and he eventually managed to reach a blistering 3GHz at 1.165V. He claims the processors throttled themselves to avoid overheating at that speed, though—not a surprising course of action, since Magny-Cours is still based on 45-nm process technology, which is very much like running a pair of Istanbul Opterons in a single socket.