New tool: AmdMsrTweaker

[kink]

@wez: Hmm okay check if that works and let me know. It might not fix this BIOS issue as there are multiple ways to enable/disable the Turbo (globally, per core, + there's a number of Turbo P-states and a min number of idling cores, and for Bulldozer, there is an additional? mode based on the consumed power as well) - so you see, there's a bunch of settings your BIOS could be f*cking up. Atm, AmdMsrTweaker adjusts the global (boost source) and per-core settings.

/edit: maybe the mode based on consumed power is the culprit - assuming you overclock, the additional power consumption may prevent the Turbo from kicking in or lasting for longer loads. AOD might disable that mode. Just another educated guess