[Doxin]

So maybe I'm misunderstanding something here, but running a lot of idle things at slightly >0% is doable on a single core. my quadcore machine doesn't start showing hickups until the load is up to 12, implying I can run 3 fairly heavy tasks per core before it starts being a problem, I'd imagine I could run a lot more low-cpu tasks per core than that.

So why do you need a lot of cores for multitasking like that again?

[dom0]

The issue is not the "idle >0%" processes, it's about compiling, indexing, searching etc. code which is often CPU-bound (because everything is in the page cache).