Slowdown when entering/leaving combat

[Psychophan7]

The strangest thing happened when 3.3.5 came out, I started getting massive slowdown when I would enter or leave combat. Without addons enabled, there is no such slowdown. What's interesting is that for every addon I turn off, the amount of slowdown is reduced, with some addons having a greater impact than others.

Anyone have an idea of what's going on?

[Chibi]

That's just addons gearing up and down, using spikes of cpu cycles or shuffling large amounts of variables (memory usage is one of the lowest impact stats, but it still has an impact when it's growing or shrinking rapidly) The enter/exit combat lag is usually caused by combat meters (skada/recount/recap) or other addons that do significantly more work in combat, like some unit frames/HUDs things like that.