Yosemite Running Slow

John Varela

Ever since I installed Yosemite my iMac has been running slower than any prior version of OS X I've used, all the way back to 10.4. I get jumpy movement of the cursor and jitter in Youtube videos. These are things I've never seen before.

It has been suggested that I find and run a program called LionSpeedMac. This program "will reorder the priorities of [my] Mac back to those found in the former Lion OS". Is anyone familiar with this program? What can you tell me about it? It's not in the App Store nor MacUpdate. Can you tell me where to find it?
Open Activity Monitor, click the "% CPU" tab, and look for hog processes. You might have to click the tab twice to order the highest on top.

Also, what iMac do you have, how much RAM, disk, ...? I have never heard of LionSpeedMac - neither has Google.
Thanks for the suggestion but that was done long ago. I find WindowServer often using 30% of a core with peak usage as high as 80%.

iMac 27" late 2009 Core 2 Duo 3.06 Ghz 12 GB.

Problem is worst when running Parallels Desktop, which uses a whole core, along with EyeTV. Mavericks and earlier could handle that. Yosemite shows jerkiness even with lesser load on the system.

I've done everything I can think of, up to and including wiping the drive and reinstalling Yosemite. Other things tried: uninstall Flash, change browsers from Firefox to Safari, uninstall all performance panes from System Preferences, remove all denials of access from Little Snitch.
Earlier this week, my "mid 2011" system (see signature) was very slow and actually froze up twice. A colleague looked at the console and noticed quite a few of these nasty items:

Dec 15 21:41:56 server kernel[0]: disk0s2: I/O error.​

Tuesday morning, it went totally belly-up. I am now booted from an external disk with a SuperDuper clone. UPS is supposed to deliver my new iMac this afternoon. I sincerely hope this isn't your problem.

By the way, I learned of "Little Snitch" only yesterday. Is it worth it?
The reason for that feeling of reduced performance can be due to a variety of issues, and most of them are really easy to resolve with surprisingly little effort.
1. Disable The Eye Candy Transparent Windows & Effects
2. Disable Unnecessary Widgets & Extensions in Notifications Center
3. Clear Off a Cluttered Desktop
4. Change the Minimize Window Effect to Scale
5. Check Out Activity Monitor for Obvious Culprits
6.Speed Up New Finder Window Generation by Changing All My Files
This is what I find online and hope it helps.
There might be various reasons behind running slow Yosemite OS, few solutions, here i am discussing with you as-
  • You can Repair Permissions:
-After this you do not have to restart your PC, but if you want to access this application from the Recovery Partition which is automatically created with new installations of the operating system.

  • Check Disk for Errors:
-This is the other way by which you can Verify your disk/hard drive, but unable to fix any issues.

  • Reset the System Management Controller (SMC)for MacBook Pro:
-Turn off your Mac
-Plug in your Mac power cord into the wall socket
-Hold down the Left Shift + Option + Control + Power Button, simultaneously, for about 10 seconds
-By doing the key presses listed above, your Mac won’t power on but the reset will be done
-Release all keys after about 10 seconds and turn on and run your Mac like you normally do

  • Reset PRAM:
-Turn off your Mac
-Press the power button
-Press Command + Option + P + R in combination, all together, before you see the initial startup screen
-Press and hold until your Mac restarts
There is the blog post Speed Up OS X Yosemite Mac or the way that worked for many people run the free EtreCheck and run it. It will show you in Red the incompatible services and the path to where to manually delete those files, then after that immediately reboot. This will speed up your Mac.
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Initially I was also facing slow Yosemite Mac issue. But I won’t recommend to go for Resetting SMC and PRAM portion. Rather very firstly go for the standardized speedup measurements like repairing file permissions, turning off unused OS X features like Bluetooth, file sharing feature, organizing desktop and managing sufficient free drive space etc. after this, still Mac is slow then SMC and PRAM part is suitable to proceed.