I agree at a gut / instinct level with that thought. SINGLE thread best and worst case have to be the same to avoid speculation... However for threads from co

I agree at a gut / instinct level with that thought. SINGLE thread best and worst case have to be the same to avoid speculation... However for threads from completely unrelated domains could be run instead, if ready. Most likely the 'next' thread on the same unit, and worry about repacking free slots the next time the schedule runs. ++ Added ++ It might be possible to have operations that don't cross security boundaries have different performance as operations within a program's space. An 'enhanced' level of protection for threads running a VM like guest code segment (such as browsers) might also be offered that avoids higher speculation operations. Any operation similar to a segmentation fault relative to that thread's allowed memory accesses could result in forfeit of it's timeslice. Which would only leak what it should already know anyway, what memory it's allowed to access. Not the content of other memory segments.