Ask HN: Speculative Multithreading- Any hope for power savings?

So I've been re-reading some material on SpMT. I seem to recall that Soft Machines was advertising better power efficiency from SpMT prior to being bought out by Intel. Given the very nature of SpMT being very aggressively speculative, it seems like it would be something that gives up power efficiency for more performance. In theory, I suppose that if the uthreads created consistently had a high probability of being valid, then it could potentially lead to some power savings compared to an expensive OoO engine while still providing decent (or better) performance. Still, it seems SpMT is unlikely to be power efficient compared to your traditional OoO. Anyone have any thoughts or relevant information?