I have a cMBP 2012. This thing has run like a champ since August 2012 when I got it, Ive NEVER had an issue with it, ever. Ive also had a Samsung 830 and 8GB of RAM installed since practically Day 1 as well. Two days ago, I had tons of tabs open in Chrome, doing my thing as usual, and my computer crashed. Got the rainbow ball, and proceeded to manually power down and restart the computer with the power button. It cut back on, no Apple logo appeared, it would NOT BOOT. I was able to boot into the diagnostic, though it started and hung 12sec in, at the memory test, every time. When holding the option key during boot, the drive was not there. I was able to boot into disk utility, wipe the drive (it showed there), but when I go to install Mac OS, it doesnt detect the drive, in fact it hangs when the computer is detecting drives to install to. Tried to reset PRAM and SMC, nothing. Took out the SSD, put in the stock 500GB drive, same thing. Took it to Apple, the young lady was of some help but wasn't very techie. She was able to run their diagnostic, and detected no problem from any of my components. She was also able to get the OS to install over the network. Long story short, it was able to install, but performance is unbearable. Takes forever to boot, Nothing is open and takes Safari 7-10 seconds to open, it stutters when switching between tabs (3 are open), mind you this is a machine with a quad i7 and 8GB of ram. Even when pressing the keyboard or display lights it takes a second for the icons to pop up on the display. Tried resetting pRAM and SMC again, nothing. Whats wrong with my Macbook PRO?!