I have not had to troubleshoot a wonky Mac in many years........

[GGD]

Robert M wrote:
JPK,

I haven't seen anyone recommend creating a new user account and seeing if the issues affect the machine while logged into it. Definitely a useful tool for troubleshooting issues. If the issue affect the main account _and_ the test account, then it is likely a system-wide problem. If the issue vanishes while logged into the test account, then it's more likely specific to the primary account.

Robert

GGD wrote:
What OS?
How Much RAM
How much disk space used, how much free?
What operations are slow?
Have you looked at Activity Monitor to see what the system is doing?
Have you tried logging out of this user and logging in as a Guest or test user? Does the performance change?
Have you tried doing a Safe Boot (shift key down), and choosing Shut Down when it gets to the login screen, and then restarting?
Have you looked at the Console Logs to see if anything strange is being reported?
As others mentioned, check SMART status with SMART Utility.