It's not the difficulty we are discussing, but the sudden jump overnight. Under normal conditions it rises steadily.
In your top post you said difficulty jumped over night. Now you are saying that your not talking about difficulty? What are you talking about then?
Difficulty jumps, up or down, every 2016 blocks, that may be overnight when it happens, but it happens after 2016 blocks.
Sam
Ya I'm a little confused by this as well. The difficulty jumped (as it does every 2016 blocks), but you're treating it like we gained 2.5TH/s with that jump, which did not happen. The network WAS slowly increasing over the past 2 weeks, but it was jumpy as always.
Now that does show the 3-day average dropping ~2TH/s from 9/3 to 9/5, but then jumping up ~4TH/s from 9/5 to 9/8.
IIRC, BFL just shipped a bunch of Singles, almost clearing their backlog. With other FPGAs and who knows how many new GPU farms, it is a sudden rise.