Hi all, I have a MBP 15" early 2011, i7 2.0, 4GB RAM version. The previous owner installed a 512 GB Apple Toshiba SSD on it. The machine is in pristine condition, but it suffers from the dreadful kernel_task eating the CPU symptoms after a while of running graphics heavy task. Restarting does not help solve it, but it's very strange that a sleep will solve the problem immediately, so I pretty much suspect Sierra does not like that laptop.... However I am tired with this and am thinking of downgrading the OS X to stabilize it. Does anyone have the same experience? If yes, any recommendations? Thanks.