Why is my Macbook Pro only running right when I am performing "repair disk permissions"

Question

Greetings,
My mid 2012 macbook pro began running extremely slow.  I have performed all of the basic diagnostics from the help threads with no luck.  In the process, I noticed that when I perform the repair disc permissions feature in disc utility, the computer runs just fine.  When this process is complete, the computer is back to running slow.  Any idea what's going on?

Answer 1

Have you tried:
Repair the Hard Drive and Permissions - Yosemite, Mavericks, Mountain Lion or Lion
Boot to the Recovery HD:
Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Repair
When the recovery menu appears select Disk Utility and press the Continue button. After Disk Utility loads select the Macintosh HD entry from the the left side list.  Click on the First Aid tab, then click on the Repair Disk button. If Disk Utility reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit Disk Utility and return to the main menu. Select Restart from the Apple menu.
If that doesn't help much then try:
Reinstalling OS X Without Erasing the Drive
Boot to the Recovery HD: Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.
Reinstalling OS X Without Erasing the Drive
Repair the Hard Drive and Permissions: Upon startup select Disk Utility from the main menu. Repair the Hard Drive and Permissions as follows.
When the recovery menu appears select Disk Utility and press the Continue button. After Disk Utility loads select the Macintosh HD entry from the the left side list.  Click on the First Aid tab, then click on the Repair Disk button. If Disk Utility reports any errors that have been fixed, then re-run Repair Disk until no errors are reported. If no errors are reported click on the Repair Permissions button. Wait until the operation completes, then quit Disk Utility and return to the main menu.
Reinstall OS X: Select Reinstall OS X and click on the Continue button.
Note: You will need an active Internet connection. I suggest using Ethernet if possible because it is three times faster than wireless.
Also see:
Reinstall OS X Without Erasing the Drive
Choose the version you have installed now:
OS X Mountain Lion- Reinstall OS X
     Note: You will need an active Internet connection. I suggest using Ethernet
                 if possible because it is three times faster than wireless.