Hi everyone, I upgraded my Macbook Pro (500 gb HDD & 8 GB RAM) from Mavericks to Yosemite and ever since then I have been getting long startup times (2 ~ 4 minutes). When I do manage to log in then the laptop will occasionally get beachballs every 15 ~ 30 seconds and will hang there for a few seconds and is almost unusable. To top it off it takes long to shut down the laptop and this can take anywhere between 15 seconds to 5 minutes (it will stay on the black screen). Things I have tried: - Clean installation of Yosemite (same result) - Reset PRAM - Changed Hard Drive - Changed RAM - Verify/ Repair Permissions. - Turned off FileVault - Cleared the kextcache - Ensured Startup disk is set correctly - Booted in Safe mode (same thing happens but worse - slow startups and restarts ) I now do not know what else I could try to do to fix this Macbook Pro and wanted to ask if anyone else has had this problem and managed to fix it? Thanks in advance.