I'meant that affinity makes a thread more energy efficent if it works alone on 2-core piledriver module, for example two threads working on one module, sharing the 2MB cache make max 40H/s each, while one thread working alone on 2-core module has 60H/s and thats because it has all the 2MB L3 for itself.
Efficency depends on algo's demand for memory, CryptoNight works best with 2MB and I realy don't know about other algos.
To make sure I need to plug my rig to power meter.
I will try tomorrow if its really more efficent and post the results.