Q: MacBook performance at rock bottom after Yosemite update

I'm having the EXACT same issues, same computer/year, everything.  except i never downloaded java. was anyone able to figure this out? i left my FireVault up over night and the progress bar shows that it's complete, yet it says "estimated time remaining" and thats it. my computer is running SO SLOW now tho. it takes forever to do ANYTHING.

Same as me. Upgraded to Yosemite and everything has slowed down. Late 2011 15" mac.

Firevault is a trying to run but is stuck at half way for the last 3 days. Really annoying

Found a temporary solution. With normal start up system continues to lag, but by starting in safe mode most programs can be used without lag. Safe mode can be activated by pressing and holding shift while rebooting right after password is entered. Safe mode will desactivate most background programs including filevault 2 encryption. All the other programs will function well.

I activate safe mode during the day to work and reboot normally in the evening to allow the encryption to run. Hopefully all will get back to normal once encrypton is finalised.

The Issue with safe mode is that spolight will not work well.

Hope this helps somebody.

I'm jumping on board with the "same here" boat. Late 2011 (purchased in spring 2012) 13' MBP 700GB/16GB RAM. Clearly FireVault is JUNK and I wish I never enabled it. Mines been stuck about a 1/120th of the way complete for three days now and I can't disable it until it's done encrypting. I have 600+GB free on my mac and rarely use more than 2 or 3 basic task applications at once. My computer has always been very responsive until now and I'm also having the 30+ second click response problem and it's EXTREMELY FRUSTRATING! Please please someone help.

I had the same problem. My computer is a mid-2010 macbook pro, had 370GB of free space out of 500GB, and worked fine before downloading the update and activating encryption.
I found that the problem can be fixed by typing sudo fdesetup disable into Terminal. It'll ask for your password after, and should disable the FireVault encryption. You can check the status of firevault by typing "fdesetup status" into Terminal, and it should return "FireVault is off." However, if you go to system preferences, it'll still have the firevault as on. I'm not completely sure how to turn it off in System Preferences -- you may have to allow it to fully encrypt in order to turn it of? The computer is still a bit laggy but has dramatically improved.

I have a MacBook Air (2012) and updated the OS from Maverick to Yosemite overnight. The next day, my Air runs very slow !! In addition, some of my software are not compatible with Yosemite, for example: MatLab 2012a.

I tried to revert the OS back to Maverick via TimeMachine back-up. It is currently still reverting and tells me that it needs another 72 hrs to complete.

I had the same problem after installing yosemite I turned on firevault. First day fine then my mac pro started running really slow.

I called Apple Support and I was able to fix it.

All you have to do is go to disk utility in applications - choose your hard drive and then click on verify disk (should take 1 to 5mins) if it says that your hard drive appears to be OK then. Go to file (top left corner in disk utility) and choose Decryption or turn off encryption depending on what it shows there.

Go to system preferences and check progress in Firevault and leave your mac turned on until the progress is finished.

Activity Monitor - Mavericks  also Yosemite

Activity Monitor in Mavericks has significant changes

Performance Guide

Why is my computer slow

Why your Mac runs slower than it should

Slow Mac After Mavericks

Things you can do to resolve slowdowns  see post by Kappy

Why are all three of my Macs and all three of my MacBook Pros loading at a glacial pace once I upgraded to Yosemite ?  I let them stay on overnight after installing and rebooting a few times.  My newest Mac with 24GB of Ram and fusion drive used to boot in about 30 seconds.  Now it's more like a minute and change.  I can now time Safari with a calendar.  Worst of all I keep losing connectivity with my Apple bluetooth mouse on my one MacBook Pro.  I have to keep resetting the PRam to get the mouse back (so I can rediscover it).  I take it that many others must be experiencing the same problem(s).  Suggestions ?

Why not just downgrade to Mavericks? It's not that hard to do, especially if you have a Mavericks Time Machine backup.

Yes, you can downgrade to Mavericks, but it will take at least 4 days. I downgraded mine last Friday, and it's still "updating" and will be done tomorrow.

I just hope there will not be a problem tomorrow after the start-up.

Hi Jon From Canada both myself and my husband are having exactly the same issues, it is sooooooo sloooooowwwwwwww since yosemite upgrade and our magic mouse keeps losing connections every 2/3 mins we are seriously considering going into apple and trying to get a genies to look at them its not the mouse because it has new batteries and its reading 82%we both have a late 12 MBP with retina 12GB and they both stopped working as soon as we upgraded.  Very annoyed to say the least, apple is supposed to "just work" GRRRRRRRRR