AMD Ontario APU pictured,die size ~77mm^2

[kl0012]

And with this half clock L2 Bobcat is supposed to be on par with Core based Pentium's we have today.

Well... You are funny man...

iirc there were some pretty significant core differences between Coppermine and Katmai as well, so you cant attribute the full performance difference only to the L2 design.

There were additional improvents (such as better instruction stalls handle) but the perf improvements was mostly from faster cache.