El Capitan running slowly?

My only suggestion would be to try starting up on a clean external installation of El Capitan, give it a couple of days to do all it's background stuff and see if the speed is good again. If it's not, that would tell you your computer is the culprit. I experimented with El Capitan on an SD card for a few weeks before changing systems. But be aware that from the SD card the system ran a bit slow. So if you can run from an external HD that might work better.

Then if all works well start using your non-apple apps one at a time to see if one of them might be the culprit.

Second suggestion would be to make a full Time Machine backup, wipe your HD clean and reinstall El Capitan. Run that for a few days and see if speed is okay. That would isolate any non-apple products, any HD problems and any "Library" corruption that might be causing problems. Then if this option works pull the other stuff from the Time Machine backup and see what happens.

Sorry you are having issues with El Capitan. I guess I am one of the lucky ones having only had a couple of minor issues.

Yep. Looks like i'm going to have to spend more dosh on an external drive & try that. I have my old disk drive with my windows stuff on but there's no-way i will ever put anything from apple on that. At the moment i can't even run the original cd installs, as i mentioned in a previous post my dvd/cd drive has died again.That died a week or so after the last so called service..Thats the second one.. It just goes on & on with this pos..My old Median computer came from an Aldi cheap deal. Never had a problem with it until the chip on the motherboard gave up after a number of years. Thats when i decided to get this, BIG Mistake, I should have tried to get another motherboard.. Trouble is do i carry on spending on this. Will it ever be worth it. Just had another beachball arrive. And all i have running is safari writing this..Where's my shot gun.

simply checking your console log, / activity monitor will give you much faster insight into the CPU usage culprit. then you can search for best steps to take from there instead of re-installing etc. To me, your approach seems unneccessary and takes too much time. I solved my issues within 10-15 min.

if you look into activity monitor / console log (within your utilities folder) - you can easily see what takes up most cpu.

How do yo get into the activity monitor when you have beachballs everywhere and you can't do anything because everything stops working? Even the activity monitor stops as i have left it open just for that purpose in the past..

Anyway, i have now completely sorted my iMac and it won't be anymore problems i can assure you.. Both barrels did the trick and i must say i got a great deal of pleasure out of it. Now going to see if i can find a medion cheap so my good lady can have her laptop back. Bye all & thanks for all your help trying to sort the pos iMac. Hope you all get your's sorted soon & have no more problems.

My reply was to sprintmick. I am presuming he has already done all the suggestions in this thread. The "Activity Monitor" is one of the first suggestions. If all the suggestions herein have NOT been tried then one should start from the beginning and go through them.

To sprintmick Not sure what you mean by "sorted", does that mean you did get it working? Or does the "both barrels" mean you too a shotgun to it?

Yes, iCloud looks like the culprit. Checking network may take a while, on WiFi it is worse. Disabled iCloud and woke up from the pinwheel nightmare.

Just to bring everyone up to date. Back in Oct. I identified the exact times of several functions on my MacBook Pro. Logan Susnick commented that it might be due to my "old" MacBook. That turned out to NOT be the case. After allowing my computer to do all the syncs with iCloud and Spotlight (took several days) I was right up to speed. I then had the "Mail" problem (which I fixed with the suggestions in this thread). Since then I have had no problems at all. Sometimes when I get over 15 apps running at the same time it slows down a little.

Yep ,Took it down the field today and shot it with both barrels. Result = no more problems.. Rip iMac (sorted)

New machine should arrive tomorrow. The wife can have her laptop back then.. Before anyone asks NO the new one is not a mac.

Take care all

Mick

This helped me. I had to do it more than once though. I don't use Mail so had no problems with that. I have 16GB RAM and nothing in CPU or Memory on Activity Monitor was showing as hogging. Every time I tried to open a Finder window I'd have the beach ball.

I completed this step and in addition:

1) System Preferences-> Users and Groups->Login Items

-Remove any unnecessary items

-In particular, removed Adobe Resource Synchronizer app was starting up at login every time and has been associated with slow loading times

-checked Library->LaunchAgents for any reference to these apps

2) Checked Activity Monitor for any rogue processes particularly Mac_Swapper Demon

-used to use a dongle but no longer do so forced quit Mac_Swapper Demon and ensured this was deleted

3) Quit Word and other Office programs which were horrifically laggy.

4) System Preferences->Spotlight

-unchecked everything apart from Applications

-unchecked Allow Spotlight suggestions

5) System Preferences-> Dock

-Minimise windows using SCALE EFFECT

6) System Preferences->Accessibility->Display

-Reduce transparency

7) Uninstalled and deleted old Blackberry Desktop Managers, Perian, other third party apps that I no longer use

8) Shut down once again, completed the Cmd+Ctrl+Shift step AGAIN...

9) Opened Spotlight and searched for KeyChain Access and I saw a blue bar with 'Indexing' appear... waited until this disappeared before touching the MacBook. Completed Keychain First Aid on Keychain Access and all seems to be working now...

Couldn't tell you which of these was the helper but try them all!

Thanks…. Now my mail seems to be working just as it did before the update. THANKS

Seemed to work after the .zip files were dumped. Then everything sprang into life again! Thanks so much for this.

Miguel,

Do you mean that i should delete all the files in the ~/Library/Containers/com.apple.mail/Data/Library/Logs/Mail/ folder, or just those that are zip files? Or just those that end in .log?- Andy

Hi - I ditched all the .log files to start with and that had no effect as they started coming back in again. When I binned the zip files, everything was OK. The zips have stayed away and the log files come back. It hasn't affected anything so I guess they create themselves but the zips are not required. So my advice is to start with everything! Hope this helps.

I have the same problems that everyone else is having (mid-2010 iMac, 8gb, 2.8ghz). I've tried the same solutions that everyone else has tried, and all I'm getting is more pinwheel of death.

I left it on over the thanksgiving break; no difference.

I left it off overnight; no difference.

Reseating the memory, resetting the PRAM, resetting the SMC, all done, no difference

It isn't iMail--isn't even running. Never use it. Went into it anyway and deleted an old account, and checked the log files; no difference.

It isn't iCloud--don't use it.

It isn't contingent on what I'm doing--the problem happens in Outlook if that's the only thing that's running, Word if that's the only thing that's running, Safari if that's the only thing that's running.

Killing spotlight and all its works and all its false promises and lies made no difference.

No significant usage of any resource visible in Activity monitor.

It doesn't crash, it doesn't refuse to launch, it just pinwheels CONSTANTLY. Like you'll be writing an email and mid-sentence it'll pinwheel for no reason for thirty seconds and then catch up before doing the same thing again. That activity monitor shows NOTHING GOING ON is perhaps the biggest problem that I have with this because all that's telling me is that activity monitor is no longer a reliable metric for gauging what it's doing.

I NEVER do upgrades because I'm fearful that something like this will happen, and fairly or not, this experience has completely vindicated those fears. I will keep using Apple products but there's no way I'll ever be doing an OS update again. I did the iOS 9 and El Capitan updates on the same day, and they have destroyed the functionality of all three of my apple devices. Live and learn: Software updates will happen in the future when buying a new device. In the meantime, is there ANYTHING that I can do to make my iMac healthy short of a full reinstall?