AMD presents "The Bulldozer Blog"

[terrace215]

If my app is restricted to 2 threads, or any other number below the max, your CPU will underperform compared to the competition.

Yes, it should be particularly bad (relative to SB) at any number of active threads up to 50% of the cores in the AMD part, especially in integer work. And when the green fans see the gaming results, we'll see the five stages of grief.