He didn't talk about it, but energy usage is likely going up, so maybe if you keep doing it long enough the frequency will have to be throttled down in order to cool down.
I don't think so. If a core is busy, it's going to be consuming almost the same amount of power whether it's using one ALU or four. So the best strategy is to finish your processing as fast as possible so that you can idle, where the significant power saving happens. Basically, if the processing finishes faster, you save energy.
