For the past week, my iMac (Retina 5K, 27-inch, Late 2015) has been unusably slow if it's left unused for too long. I selected "Prevent your Mac from automatically sleeping when the display is off", which seems to have helped a bit, but when I left the machine for a couple hours earlier today I had the same problems again.
What I get is either:
1) If waking from sleep sometimes it would crash and reboot after I enter my password, with the error message being Window Server not responding for 120 second
2) More generally, and since disabling sleep, what I get is unusably slow performance. Every click creates a beach ball, but eventually most will actually produce a respond after 60 seconds plus. The iMac generally stays responsive enough for me to be able to trigger a software reboot, but the most recent time it didn't.
I have a Fusion drive, and as this is my third iMac with a Fusion drive my suspicion is it might be to blame as that's usually what goes.
Disk Utility has found no errors. I booted in to Apple Diagnostics mode and that also found no errors.
I'll probably try a wipe and reinstall next but am worried that if the root problem is hardware I might end up in a worse state.
Anyone seen similar problems and can offer advice?
What I get is either:
1) If waking from sleep sometimes it would crash and reboot after I enter my password, with the error message being Window Server not responding for 120 second
2) More generally, and since disabling sleep, what I get is unusably slow performance. Every click creates a beach ball, but eventually most will actually produce a respond after 60 seconds plus. The iMac generally stays responsive enough for me to be able to trigger a software reboot, but the most recent time it didn't.
I have a Fusion drive, and as this is my third iMac with a Fusion drive my suspicion is it might be to blame as that's usually what goes.
Disk Utility has found no errors. I booted in to Apple Diagnostics mode and that also found no errors.
I'll probably try a wipe and reinstall next but am worried that if the root problem is hardware I might end up in a worse state.
Anyone seen similar problems and can offer advice?