Well, it's a bit of the whole image. Of course, swapping is also slowing a machine down. But this problem always existed on single core computers too, the 99% application problem. That problem would completely halt a single core computer, but a dual core computer would work just fine even if a process went up to 50%.

I've had uncountable computers, but I feel there has been two particularly noticeable leaps in hardware experience; dual core technology made computers not hang, solid state discs made computers boot fast.

What I'd have liked, regardless of single core or dual core, was that a given amount of memory and cpu either were completely reserved, or at least gave prioritized access to a "real time event" priority list. So that the GUI would work and the phone app would start, even if something else were chewing up CPU+RAM.