I currently have a 15" MBP (early 2011) 2.0 core i7. It has worked perfectly since I got it. Then I upgraded to Yosemite. Since upgrading the computer is extremely slow and takes forever to open up apps, often freezing up completely. Also it has started to just turn off randomly. It is becoming unbearable. I am thinking about upgrading to an SSD drive and upgrading the ram. Would this fix my problems? And is there anything else I can do to get my MBP back running how it was before the OS upgrade?