We never write changes to disk, the code is trivial really. And it always launches from a locked snapshot. What we are always trying to optimize is the time to

We never write changes to disk, the code is trivial really. And it always launches from a locked snapshot. What we are always trying to optimize is the time to the user screen. That is really the expensive part, once the disk reads happen we want a working session on the users screen as quick as we can get it. Or that is the plan anyway. :)