I have a small theory that I'd like to put out to the community (mostly to prove that I'm not, in fact, insane)....
I've noticed lately that the widget (or whatever you want to call it) in the top left corner with your name, score, etc. has an effect to it that pops up every once in a while. It's a sort of glimmer or glean effect. I've noticed lately that when this happens I get a moderate to significant spike in my swing meter. I'm guessing that because it is an animation that happens when everything else is still, it is causing a cpu spike. This seems similar to the issues I had before there was the ability to turn the flag animation off. My putting meter in those conditions was severely affected by the animation of the flags. (I run a bare minimum requirements system) Of course if my theory is correct, then multiplayer rounds will probably be compounded by this event depending on the number of players.
So please keep an eye on this visual effect and any relation to swing meter smoothness, and report any findings back here.
NOTE: This is a constructive thread to prove or disprove a particular theory, it is not intended to become a b*^&$ fest over the meter, the beast, or the so-called vemmie.