I've got a late 2008 Macbook Pro (first of the Unibodies) that's now out of OS support (it's on 10.11, and will forever be there), is generally slow until it's caught up with booting or waking up, but ...

I can confirm it fixed my flicker problem. I didn't save a copy of the system profiler before the update, below is after the update. My MacBook seems to run a little cooler too. Code: Hardware ...