El Capitan running slowly?

Thanks for the description of your actions and the resulting improvements. I still find it frustrating that Apple cannot design an OS upgrade that doesn't require a degree in Computer Science and detailed knowledge of the technology just to get it to work.. This is not what I bought Apple products for... I expected they made life simpler for users but I am obviously wrong.... and I'm still a very unhappy customer after spending over 2 hours on the phone with Apple support yesterday! Very frustrating!

Duh - maybe BETA testing should not be with the experienced savvy Apple users -- as they are not the ones who will have problems post release - their systems and files are probably whistle-squeaking clean. Test with real-world non-savvy users who have 'dirty' but realistic systems filled with obsolete files etc.

I so agree with northern cyclist btw. we shouldn't have to sort through thousands of email, know how to program or be left on our own to muddle up our systems by following un-vetted advice.

Please do not issue 'updates' or do de-bugging after the release. Any realistic user-experience testing would have found the exact same issues found post release. Key world here is 'realistic' or real world - not a universe of Apple experts.

I have an old MacPro 3,1 and updated yesterday to El Capitan. Like the messages before I ran into the same lag/slowness issues (not to mention the 2hr installation time....whew). Anyway, I did what was recommended by the earlier emails of resetting my pram and that helped a lot. Those with the mail tool issue I found that I did not hit that issue because I keep my mac mail down in size by archiving off my mail yearly. It's extremely simple to do.

Make an archive email folder in mac mail and drag and drop all emails you want to archive off. Then simply right click and export it to another drive. You can create multiple export folders if you have a substantial email. Once you do that you can delete the email archive folder in mac mail. Rinse and repeat as often as you want. This will resolve your mail tool's issues. In my case my email tool doesn't even come close to 1GB and runs fast and smooth and I have nearly 15 years of emails from my prior macs that I can access archived off.

Resetting Spotlight and giving it uninterrupted indexing time helped. Mac is still slightly choppy.. The firmware re-sets did not:

- System Preferences/Spotlight/Privacy: In the Prevent Spotlight.... window, I added my entire Macbook Air drive (13", mid-2013).

- Reboot. You should notice that Spotlight can't find anything, including applications

- System Preferences/Security & Privacy/Privacy/Advanced: I unchecked the "Log Out ...." box so that indexing is never interrupted. My screen was still set to lock after 1 minute

- Shut down all applications, plugged in the Mac

- System Preferences/Spotlight/Privacy: In the Prevent Spotlight.... window, I removed the prohibition from indexing my drive (13", mid-2013).

- Left the computer on over night.

The next day, everything worked fine, except Mail which kept crashing. I reboot somewhat solved the problem, but Mail is a bit choppy and still occasionally crashes. Best of luck to all.

deleting the log files did the trick!!!

My internet was terribly slow after upgrading to el capitan--Safari would start out okay, but after a few minutes completely stop while loading pages.

My solution (after reinstalling el capitan, unplugging/replugging my modem router, deleting the wifi connection and reestablishing it, and a whole slew of other "solutions") came from something so simple--I rebooted my modem via the IP address.

Logging in and rebooting it that way reset it in a way that I couldn't accomplish physically, so it's definitely worth a shot. And trust me, this took me hours of troubleshooting and almost swearing off Macs forever.

ANY PROBLEMS WITH SLOW PRINTING???

Thanks Miguel.apple - I had the problem with the memory hogging mail app - spent 2 days rebuilding and leaving to try to index thinking that was the problem, when all along it was as you say - a very large c. 40GB .log file that was the problem .... deleted .log files as you suggested + mail works fine .... simple as that ! Cheers

For me, it was the FileVault that was turned on so i reinstalled El Capitan and then it ran smoothly again!

Hope it helped

Thanks man, both my macs were using all the memory - iMac would crash out at 16Gb, the MPBro would happily work with 64Gb of memory used (machine has 16Gb)

Both machines had zipped log files over 100Gb in size, now both are working.
Absolute star!!

ATab,

Cool! I didn't know you could manipulate Spotlight to that degree. I'm going to have to try that. My guess that the people deleting large log files are simply taking work away from Spotlight so that it is not bogged down indexing them.

My computer is finally running normally. This is what I did...

0) BACKED UP MY MAIL AND COMPUTER!!!

1) Reset P-RAM. Holding CMD+OPT+P+R on startup until the second boot. Checked Activity Monitor after this. Mail still gobbled up more and more RAM.

2) Erased the Mail Logs. Although none of them were huge. Checked Activity Monitor after this. Mail still gobbled up more and more RAM.

3) Chose "rebuild" from the Mail->Mailbox. Checked Activity Monitor after this and everything was back to normal.

My iMac was running beautifully since i recently upgraded my memory to 16GB. PS and Corel Painter were zipping away, it was such a pleasure and then I could just kick myself i upgraded to that El Capitan and now my iMac is running the same way it was before I upgraded the ram from 8GB. I wish there was some way I could go back to Yosemite. Now I am stuck with that stupid spinning dial. Think I will have to go back to working on my macbook till Apple resolves this issue. I am a digital artist and need to work with a decent computer with a nice big screen, this one is not usable for my work anymore. Oh and i read some of the replies here and my Mail isn't running when when I am working. Unless someone knows how i can reverse an upgrade Im stuck???? Anyone anyone???

You can do an Internet recovery back to the OS that came with your iMac.

Erase your HD and restore from your backup.