Q: El Capitan running slowly?

Try try running this program and paste the results in a reply.

Etrecheck – System Information

I am experiencing substantial delays when opening and switching applications and screens in El Capitan. Pinwheel nightmare.

Note that the first thing the computer will need to do after upgrading is a full Spotlight reindex of your drive, something that will take significant computing and I/O resources.

If the speed issues still occur 24 hours after installation (after leaving the computer on overnight), then more investigation is needed.

it runs about same as yosemite on my macbook pro, but my mac pro became horribly slow, might say even my old powermac G5 runs faster at the moment...

I have same issue as yours, even I type my user name and password.

same  issue here, I get the spinning wheel every time i click something. Any solutions?

I too am having slow performance upon downloading El Capitan last night.  I tried to send an email and my iCloud account wasn't recognized.  I solved that issue by opening System Preferences > iCloud then unchecking mail.  I then restarted and re-checked it and it worked.  But everything is running slowly.  I'm posting the results of my EtreCheck in the hopes someone here may help!

EtreCheck version: 2.5.1 (203)

Report generated 10/1/15, 8:27 PM

Download EtreCheck from http://etresoft.com/etrecheck

Click the [Click for support] links for help with non-Apple products.

Click the [Click for details] links for more information about that line.

Hardware Information: (What does this mean?)

    MacBook Pro (15-inch, Mid 2012)

    [Click for Technical Specifications]

    [Click for User Guide]

    MacBook Pro - model: MacBookPro9,1

    1 2.6 GHz Intel Core i7 CPU: 4-core

    8 GB RAM Upgradeable

    [Click for upgrade instructions]

        BANK 0/DIMM0

            4 GB DDR3 1600 MHz ok

        BANK 1/DIMM0

            4 GB DDR3 1600 MHz ok

    Bluetooth: Good - Handoff/Airdrop2 supported

    Wireless:  en1: 802.11 a/b/g/n

    Battery: Health = Normal - Cycle count = 110 - SN = D862444R0Z8DGDMB9

Video Information: (What does this mean?)

    Intel HD Graphics 4000

        Color LCD 1440 x 900

    NVIDIA GeForce GT 650M - VRAM: 1024 MB

System Software: (What does this mean?)

    OS X El Capitan 10.11 (15A284) - Time since boot: less than an hour

Disk Information: (What does this mean?)

    APPLE HDD HTS727575A9E362 disk0 : (750.16 GB) (Rotational)

        EFI (disk0s1) <not mounted> : 210 MB

        Recovery HD (disk0s3) <not mounted>  [Recovery]: 650 MB

        Macintosh HD (disk1) / : 748.93 GB (607.61 GB free)

            Core Storage: disk0s2 749.30 GB Online

    MATSHITADVD-R   UJ-8A8   ()

USB Information: (What does this mean?)

    Apple Inc. FaceTime HD Camera (Built-in)

    Apple Inc. Apple Internal Keyboard / Trackpad

    Apple Computer, Inc. IR Receiver

    Apple Inc. BRCM20702 Hub

        Apple Inc. Bluetooth USB Host Controller

Thunderbolt Information: (What does this mean?)

    Apple Inc. thunderbolt_bus

Gatekeeper: (What does this mean?)

    Mac App Store and identified developers

Kernel Extensions: (What does this mean?)

        /Applications/Lacie DVD/LaCie DVD Update Tool.app

    [not loaded]    com.LaCie.ScsiType00 (1.2.1) [Click for support]

        /Applications/Toast 9 Titanium/Toast Titanium.app

    [not loaded]    com.roxio.BluRaySupport (1.1.6) [Click for support]

    [not loaded]    com.roxio.TDIXController (2.0) [Click for support]

        /Applications/Utilities/DiskWarrior/DiskWarrior.app

    [not loaded]    com.alsoft.Preview (4.4) [Click for support]

        /System/Library/Extensions

    [not loaded]    com.flipvideo.IOUSBCameraMassStorage (1.0.1) [Click for support]

    [not loaded]    com.m-audio.driver.firewire (1.7.4) [Click for support]

    [not loaded]    com.palm.ClassicNotSeizeDriver (3.2) [Click for support]

System Launch Agents: (What does this mean?)

    [loaded]    com.apple.java.InstallOnDemand.plist - Invalid signature!

System Launch Daemons: (What does this mean?)

    [loaded]    com.apple.airplaydiagnostics.server.mac.plist - /AppleInternal/Applications/AirPlayDiagnostics.app/Contents/Resources/AirPlayDi agnosticsServer: Executable not found!

Launch Agents: (What does this mean?)

    [running]    com.epson.Epson_Low_Ink_Reminder.launcher.plist [Click for support]

    [loaded]    com.epson.esua.launcher.plist [Click for support]

    [running]    com.epson.eventmanager.agent.plist [Click for support]

Launch Daemons: (What does this mean?)

    [loaded]    com.adobe.fpsaud.plist [Click for support]

    [loaded]    com.github.IngmarStein.Monolingual.Helper.plist [Click for support]

    [loaded]    com.microsoft.office.licensing.helper.plist [Click for support]

    [loaded]    net.sourceforge.MonolingualHelper.plist [Click for support]

User Login Items: (What does this mean?)

    Dropbox    Application  (/Applications/Dropbox.app)

    Google Drive    UNKNOWN  (missing value)

    Fantastical    UNKNOWN  (missing value)

    Fantastical    UNKNOWN  (missing value)

Other Apps: (What does this mean?)

    [running]    com.apple.xpc.launchd.oneshot.0x10000003.EtreCheck - Invalid signature!

Internet Plug-ins: (What does this mean?)

    Flip4Mac WMV Plugin: Version: 3.2.0.16   - SDK 10.8 [Click for support]

    FlashPlayer-10.6: Version: 19.0.0.185 - SDK 10.6 [Click for support]

    QuickTime Plugin: Version: 7.7.3

    Flash Player: Version: 19.0.0.185 - SDK 10.6 [Click for support]

    Default Browser: Version: 601 - SDK 10.11

    SharePointBrowserPlugin: Version: 14.5.5 - SDK 10.6 [Click for support]

    JavaAppletPlugin: Version: 15.0.1 - SDK 10.7 Check version

User internet Plug-ins: (What does this mean?)

    QuickTime Plugin: Version: 7.6.6

    Silverlight: Version: 4.0.60129.0 [Click for support]

Safari Extensions: (What does this mean?)

    ClickToFlash

    LastPass

3rd Party Preference Panes: (What does this mean?)

    Flash Player  [Click for support]

    Flip4Mac WMV  [Click for support]

Time Machine: (What does this mean?)

    Time Machine not configured!

Top Processes by CPU: (What does this mean?)

         4%    WindowServer

         2%    fontd

         0%    mdworker(10)

         0%    cloudpaird

Top Processes by Memory: (What does this mean?)

    656 MB    kernel_task

    311 MB    com.apple.WebKit.WebContent

    172 MB    mdworker(10)

    147 MB    Safari

    106 MB    WindowServer

Virtual Memory Information: (What does this mean?)

    4.38 GB    Free RAM

    3.61 GB    Used RAM (1.48 GB Cached)

    0 B    Swap Used

Diagnostics Information: (What does this mean?)

    Oct 1, 2015, 08:19:12 PM    Self test - passed

I instaled it first on my White Macbook, one of the latest in its kind. It has 6GB Ram and a SSD.

It works like a speer! So incredible fast!

So, happy as I was, I installed it on may Macbook Pro i7 8GB RAM. A complete disaster!

So slow, beachballs all over the place.

iPhoto doesn't works any more, and can't be downloaded . (foto's is a disaster). I 'm not amused.

Having the same issue.  The apps are very slow to start.  It seems that the icons bounce on the dock for ages before you can start using an app.  I have a 2014 Mini, the middle version with the 2.6 Ghz chip and 8GB ram.  Yosemite was slow at times on it before.  I go the beach ball all the time.  Since they advertised El Capitan as a snappier version of OSX I thought it would fix the problem not make it worse.  I did a "disk repair" but it didn't help with the speed at all.  I tried everything I could from these forums and the internet to get it to speed up on Yosemite but non of it ever worked.  Very disappointed.

I also had the same issue but as suddenly as it started it ended after i did the following

(1) Basically Launched each iMac application - still slow

(2) restarted

(3) Went into Boot Camp / Opening Widows -  Msoft office, IE and Mail

(4) did an orderly shut down

(5) Turned my internet router (related hard ware off and back on)

(6) Signed into iMac Partition

(7) magically all of my speed was back.

Yes, most everything is running slowly, and Microsoft Office, System Preferences, iWork suite are deadly slow. Also, my printers have been removed, and the process of adding printers doesn't work. Very disappointing.

I have the same issues. I have a Newer iMac and the RAM is maxed out, yet every move of the cursor brings up the pinwheel. I get this problem just trying to move a file on the desktop. iTunes, which has been slow and bloated for the last several versions is even worse. I'm really disappointed.

So I have no idea what happened but the Mini is now running better than it did before El Captitan.  I installed it last night and it was running VERY slow.  I went to bed and didn't touch it until I got home from work and huge improvement! I'm thinking maybe it had to run through a bunch of processes or something.  it goes into sleep mode, however I have it setup on power nap, so maybe that was it, who knows.

I believe I may have found the problem (at least mine) or maybe one of the problems.  I updated my MBP and 2015 Retina iMac and both basically became inoperable a short time after the upgrade.  After some poking and prodding, came to realize there may be a bug in Mac Mail.  It became a huge memory hog and kept growing in size as shown in the Activity Monitor, soaring to over 10GB in size.  It seems like Apple has a bug to fix with Mac Mail.  If I don't launch Mac Mail, the computers run fine.  I can use Outlook on one of my computers for now and it runs fine.  Mac Mail is the culprit.