I've been using my mid-2009 MBP for years (15", 2.8 GHz Core 2 Duo), but have had to hold off on the last few OS X updates because of sluggish performance on the newer OSs - even with clean installations. I'm currently running Mountain Lion (10.8.5) and recently found out that even Google Chrome won't be supported on 10.8 in just a few months. This has gotten me thinking about ways that I could upgrade my computer to improve performance and hopefully run El Capitan without being too laggy. I still have the stock 5400 RPM 500 GB HD and only 4 GB of RAM. I'm thinking of replacing my HD with the Samsung 850 Evo and upgrading my RAM to 8 GB. My question is that is this reasonable to expect good enough performance to run El Capitan on my good old mid-2009 MBP?