MacOS – WindowServer high CPU on Yosemite

Troubleshooting a slow mac is fairly easy, but sometimes tedious.

You will want to and quit all apps.

You might even go to the Users & Groups preference and remove all applications that start when you log in to your Mac.

Turn off WiFi and then shut down the Mac so you can start isolating it. Remove all peripherals except the keyboard, display and power cord. Power on and then log in and let it run for 5 minutes and then take a snapshot of the Activity Monitor. Look and see what CPU usage is and if the background tasks are taking any CPU time.

If so, dig deeper - open terminal and run "sudo sysdiagnose"

If not, go ahead and connect your peripherals one at a time.

Check the CPU/Activity Monitor and watch both the Memory Pressure graph and the CPU. If you want, you can also look at energy, but that's better for half hour snapshots for me.

At this point, you should know the OS is fine and all of your peripherals and hard drives are not causing the slowness.

Now go ahead and start the apps you choose to run when it's slow. Again, you are still disconnected from any network - just checking the OS and the CPU.

When that's fine, you can conclude that the data coming in from the network was causing a load the OS wasn't handling.

If you can narrow things down, get a sysdiagnose from a clean start and again when it is "slow" and post a second question with details of what your initial troubleshooting has shown.

Your memory and CPU usage are normal. And you don't appear to have anything massive running.

Modern computers utilize as much memory as possible before swapping anything out to the (much slower) disk. If you have more than 1-2 programs open you should expect to see the memory mostly full. The OS will handle swapping / clearing it as needed.

My computer is getting old (almost 6 years old I think) and is becoming increasingly slow.

Computers do not slow down with age. But they do accumulate stuff. How full is your disk drive? If you have less than 20Gb or 15% free space your disk will take a lot longer to return results.

Or your disk is having issues. Either way, installing an SSD is a simple and cheap way to get a huge performance boost out of an older machine. The drives cost under $200 now, changing one takes 15 minutes but on a macbook Pro will require some special screwdrivers.