Hi
I am also suffering from a very slow iMac that was only purchased just over 3 months ago.
Please find below a copy of the diagnostic run through Etrecheck.
Can you help please?
EtreCheck version: 3.0.1 (304)
Report generated 2016-08-16 22:43:29
Download EtreCheck from https://etrecheck.com
Runtime 3:39
Performance: Good
Click the [Support] links for help with non-Apple products.
Click the [Details] links for more information about that line.
Problem: Computer is too slow
Description:
it takes a long time to open from sleep mode
it is slow to open pages
it beachballs often
Hardware Information:ⓘ
iMac (Retina 5K, 27-inch, Late 2015)
[Technical Specifications] - [User Guide] - [Warranty & Service]
iMac - model: iMac17,1
1 3.2 GHz Intel Core i5 CPU: 4-core
8 GB RAM Upgradeable - [Instructions]
BANK 0/DIMM0
4 GB DDR3 1867 MHz ok
BANK 0/DIMM1
Empty
BANK 1/DIMM0
4 GB DDR3 1867 MHz ok
BANK 1/DIMM1
Empty
Bluetooth: Good - Handoff/Airdrop2 supported
Wireless: en1: 802.11 a/b/g/n/ac
Video Information:ⓘ
AMD Radeon R9 M390 - VRAM: 2048 MB
iMac 5120 x 2880
System Software:ⓘ
OS X El Capitan 10.11.6 (15G31) - Time since boot: about 20 days
Disk Information:ⓘ
APPLE HDD ST1000DM003 disk1 : (1 TB) (Rotational)
EFI (disk1s1) <not mounted> : 210 MB
Recovery HD (disk1s3) <not mounted> [Recovery]: 650 MB
Macintosh HD (disk2) / : 1.02 TB (775.34 GB free)
Core Storage: disk0s2 23.55 GB Online
Core Storage: disk1s2 999.35 GB Online
APPLE SSD AP0032H disk0 : (24 GB) (Solid State - TRIM: Yes)
EFI (disk0s1) <not mounted> : 315 MB
Boot OS X (disk0s3) <not mounted> : 134 MB
Macintosh HD (disk2) / : 1.02 TB (775.34 GB free)
Core Storage: disk0s2 23.55 GB Online
Core Storage: disk1s2 999.35 GB Online
USB Information:ⓘ
Broadcom Corp. Bluetooth USB Host Controller
Apple Inc. FaceTime HD Camera (Built-in)
Thunderbolt Information:ⓘ
Apple Inc. thunderbolt_bus
Gatekeeper:ⓘ
Mac App Store and identified developers
Kernel Extensions:ⓘ
/Library/Extensions
[loaded] com.sophos.kext.sav (9.4.52 - SDK 10.9 - 2016-08-02) [Support]
[loaded] com.sophos.nke.swi (9.4.52 - SDK 10.9 - 2016-08-02) [Support]
Startup Items:ⓘ
HWNetMgr: Path: /Library/StartupItems/HWNetMgr
HWPortDetect: Path: /Library/StartupItems/HWPortDetect
Startup items are obsolete in OS X Yosemite
System Launch Agents:ⓘ
[not loaded] 7 Apple tasks
[loaded] 142 Apple tasks
[running] 81 Apple tasks
[killed] 8 Apple tasks
8 processes killed due to insufficient RAM
System Launch Daemons:ⓘ
[not loaded] 43 Apple tasks
[loaded] 139 Apple tasks
[running] 98 Apple tasks
[killed] 10 Apple tasks
10 processes killed due to insufficient RAM
Launch Agents:ⓘ
[not loaded] com.adobe.AAM.Updater-1.0.plist (2016-06-11) [Support]
[failed] com.adobe.ARMDCHelper.cc24aef4a1b90ed56a725c38014c95072f92651fb65e1bf9c8e43c37a2 3d420d.plist (2016-07-20)
[loaded] com.google.keystone.agent.plist (2016-07-12)
[running] com.oracle.java.Java-Updater.plist (2016-04-30)
[running] com.sophos.uiserver.plist (2016-04-30)
Launch Daemons:ⓘ
[loaded] com.adobe.ARMDC.Communicator.plist (2016-07-20) [Support]
[loaded] com.adobe.ARMDC.SMJobBlessHelper.plist (2016-07-20) [Support]
[running] com.adobe.agsservice.plist (2016-08-15) [Support]
[loaded] com.adobe.fpsaud.plist (2016-06-29)
[loaded] com.adobe.versioncueCS4.plist (2010-06-27)
[loaded] com.google.keystone.daemon.plist (2016-07-12)
[loaded] com.macpaw.CleanMyMac2.Agent.plist (2014-11-08) [Support]
[loaded] com.macpaw.CleanMyMac3.Agent.plist (2015-07-17) [Support]
[loaded] com.microsoft.autoupdate.helpertool.plist (2016-01-24) - /Library/PrivilegedHelperTools/com.microsoft.autoupdate.helpertool: Executable not found!
[loaded] com.microsoft.office.licensing.helper.plist (2010-08-25)
[loaded] com.microsoft.office.licensingV2.helper.plist (2015-09-11) [Support]
[loaded] com.oracle.java.Helper-Tool.plist (2016-04-30)
[running] com.sec.faxdb.plist (2011-12-12)
[loaded] com.sibelius.sari.plist (2010-06-27)
[running] com.sophos.common.servicemanager.plist (2016-04-30)
User Launch Agents:ⓘ
[running] com.google.Chrome.framework.plist (2016-07-27)
User Login Items:ⓘ
iTunesHelper Application (/Applications/iTunes.app/Contents/MacOS/iTunesHelper.app)
Dropbox Application (/Applications/Dropbox.app)
AdobeResourceSynchronizer Application Hidden (/Applications/Adobe Acrobat DC/Adobe Acrobat.app/Contents/Helpers/AdobeResourceSynchronizer.app)
AdobeResourceSynchronizer Application Hidden (/Applications/Adobe Acrobat Reader DC.app/Contents/Helpers/AdobeResourceSynchronizer.app)
Google Drive Application (/Applications/Google Drive.app)
InstUtilLaunch Application (/Library/Printers/Brother/Utilities/InstallUtility.app/Contents/Resources/Inst UtilLaunch.app)
Internet Plug-ins:ⓘ
Google Earth Web Plug-in: 7.1 (2016-04-30) [Support]
Default Browser: 601 - SDK 10.11 (2016-07-27)
DYMO Safari Addin: Unknown (2016-04-30) [Support]
OfficeLiveBrowserPlugin: 12.3.3 (2016-04-30) [Support]
Unity Web Player: UnityPlayer version 4.0.1f1 (2016-04-30) [Support]
AdobeAAMDetect: AdobeAAMDetect 2.0.0.0 - SDK 10.7 (2016-04-30) [Support]
FlashPlayer-10.6: 22.0.0.209 - SDK 10.9 (2016-08-10) [Support]
AdobePDFViewerNPAPI: 15.016.20045 - SDK 10.11 (2016-06-08) [Support]
Silverlight: 5.1.41212.0 - SDK 10.6 (2016-06-14) [Support]
QuickTime Plugin: 7.7.3 (2016-07-27)
Flash Player: 22.0.0.209 - SDK 10.9 (2016-08-10) [Support]
iPhotoPhotocast: 7.0 (2016-04-30)
SharePointBrowserPlugin: 14.6.1 - SDK 10.6 (2016-04-30) [Support]
AdobePDFViewer: 15.016.20045 - SDK 10.11 (2016-06-08) [Support]
Scorch: Unknown - SDK 10.2 (2016-04-30) [Support]
JavaAppletPlugin: Java 8 Update 91 build 14 (2016-06-14) Check version
Safari Extensions:ⓘ
Dyslexie for Safari - ftollenaar (2016-06-08)
3rd Party Preference Panes:ⓘ
Flash Player (2016-06-29) [Support]
Java (2016-06-14) [Support]
TechTool Protection (2015-07-17) [Support]
Time Machine:ⓘ
Skip System Files: NO
Mobile backups: OFF
Auto backup: YES
Volumes being backed up:
Macintosh HD: Disk size: 1.02 TB Disk used: 246.65 GB
Destinations:
Public [Network]
Total size: 1.96 TB
Total number of backups: 19
Oldest backup: 3/08/2016, 11:03 PM
Last backup: 16/08/2016, 10:37 PM
Size of backup disk: Adequate
Backup size 1.96 TB > (Disk used 246.65 GB X 3)
Top Processes by CPU:ⓘ
16% kernel_task
2% diskimages-helper(3)
1% WindowServer
0% Google Chrome
0% Mail
Top Processes by Memory:ⓘ
1014 MB kernel_task
434 MB softwareupdated
385 MB com.apple.WebKit.WebContent(6)
360 MB Google Chrome Helper(4)
319 MB Safari
Virtual Memory Information:ⓘ
219 MB Free RAM
7.78 GB Used RAM (1.29 GB Cached)
1.73 GB Swap Used