[Torhal]

Originally Posted by nightcracker <snip>So if you run at 120 FPS your calling a sin function 120 times per second.<snip>

Not true.

do
	local last_update = 0
	local updater = CreateFrame("Frame", nil, UIParent)

	updater:Hide()
	updater:SetScript("OnUpdate",
			  function(self, elapsed)
				  last_update = last_update + elapsed

				  if last_update >= 0.25 then
					  RunSinFunction()
					  last_update = 0
				  end
			  end)
end

That executes the sin function every quarter of a second.