Thanks - this solved my problem - blazing fast now (& saved me having to do a clean install).The culprit chewing up my CPU on Yosemite was the Parallels Access agent. Set it to not start at boot and quit the program and the issues go away.
I still have problems and I have had that ever since I upgraded to mavericks. now with Yosemite beta 3, I can't even use my macbook pro anymore. Just clicking a tab takes 20 sec for it to think about it.
I have not been able to find a solution ever since mavericks was released. I am just curious, Apple innovates and innovates but when you have a macbook from 2012 which is only 2 years old, is this the way they want their computers to function. this is completely unacceptable.
i want to say that i have the full released normal final version and i have a lot of slowdown issues.
When i press the application folder in the dock it opens very slowly also the whole dock is slow.
When i open files and folders the icons or content come up slower.
everything is almost a little choppy but i did not have this problem in mvrck.
is there a solution?
There is an issue with some 2011 iMacs that seems to be related to com.apple.driver.AppleACPIPlatform
See
https://discussions.apple.com/thread/6621147?start=0&tstart=0
http://forum.parallels.com/threads/parallels-10-running-slow-on-yosemite.326205/
http://kb.parallels.com/en/122767
The solution is to run
sudo nvram boot-args="debug=0xd4e"
If this helped, please report the bug to Apple:
Visit https://www.apple.com/feedback/imac.html
Here's a sample for the "Subject" field. Please adapt it to include your specific details:
Yosemite slow on 2011 iMac - com.apple.driver.AppleACPIPlatform
Here's a sample for the "Message" field. Please adapt it to include your specific details:
After upgrading my iMac from Mavericks to Yosemite, there was a significant decrease in performance. The UI became less responsive and animations become much choppier, and Virtual Machines became slow to the point of no longer being usable. With the help of a Parallels article at http://kb.parallels.com/122767, I traced the issue to an excessive number of interrupts being generated by com.apple.driver.AppleACPIPlatform . The solution was to run sudo nvram boot-args="debug=0xd4e". Many people are experiencing the same problem - please see http://forum.parallels.com/threads/parallels-10-running-slow-on-yosemite.326205/page-2 and https://discussions.apple.com/thread/6621147 for example.
If you have an Apple Developer account, you can also file a bug report for OS X at https://bugreport.apple.com/
Please also see this issue reported on Apple forums: https://discussions.apple.com/thread/6621147
But i am not using an imac this is a macbook pro 2013
nothing happened when i ran that command.
I know the OP was writing about a DP, but I found this thread by Googling "Yosemite Slow" and I have the exact same problem with System Preferences on an OS that has been out for six months now. Everything takes forever in Yosemite: Booting takes about four or five times as long as it used to, apps are much slower to open I do not understand it. I keep my disk and permissions repaired, and I have followed steps recommended in other articles I found on Yosemite slowness, such as reducing transparency. None of it helps. What gives?
keyword - SSD...
(Bloated) Yosemite has been (badly) designed to run on newer hardware that comes with SSDs...
HDDs - tough luck...
My 2009 MacBook Pro, using a spinning HD, is no slower running Yosemite 10.10.3 then it was when I was using Mavericks 10.9.5 on the same machine. Safari 8, in Yosemite, certainly runs circles around the version in Mavericks.
Safari 8 only...? Please pay attention to the question... He's asking about the slowness of System Preferences, booting, and virtually just about everything that slows down on Yosemite...
If you want everything to run circles around Yosemite, and even Mavericks too, go downgrade to Leopard or Snow Leopard and experience the speedup yourself.
Maybe you need to pay more attention. Wow, surprised you did not suggest to the poster to downgrade to Snow Leopard or Leopard.My 2009 MacBook Pro, using a spinning HD, is no slower running Yosemite 10.10.3 then it was when I was using Mavericks 10.9.5 on the same machine.
I know the OP was writing about a DP, but I found this thread by Googling "Yosemite Slow" and I have the exact same problem with System Preferences on an OS that has been out for six months now. Everything takes forever in Yosemite: Booting takes about four or five times as long as it used to, apps are much slower to open… I do not understand it. I keep my disk and permissions repaired, and I have followed steps recommended in other articles I found on Yosemite slowness, such as reducing transparency. None of it helps. What gives?