This morning I'm suddenly seeing unplayably low fps when I'm running all five accounts. In the past when I had this problem I was able to fix it by manually setting each toon to the lowest settings on the options menu, and then using my lower/higher graphics settings macros. Today that doesn't seem to be working, everything on super low is only running at 13 fps, which gives me a headache to look at it.

I've tried closing out all of my wows and launching them fresh but no dice. What's a good next step for troubleshooting this?

It was working fine when I went to bed last night.