dominic23 -
Here is the report EtreCheck generated. Please advise. Thanks.
EtreCheck version: 2.9.3 (253)
Report generated 2016-02-04 22:13:32
Download EtreCheck from http://etrecheck.com
Runtime 2:19
Performance: Excellent
Click the [Support] links for help with non-Apple products.
Click the [Details] links for more information about that line.
Problem: Beachballing
Hardware Information: ⓘ
iMac (21.5-inch, Mid 2011)
[Technical Specifications] - [User Guide] - [Warranty & Service]
iMac - model: iMac12,1
1 2.5 GHz Intel Core i5 CPU: 4-core
4 GB RAM Upgradeable - [Instructions]
BANK 0/DIMM0
2 GB DDR3 1333 MHz ok
BANK 1/DIMM0
2 GB DDR3 1333 MHz ok
BANK 0/DIMM1
Empty
BANK 1/DIMM1
Empty
Bluetooth: Old - Handoff/Airdrop2 not supported
Wireless: en1: 802.11 a/b/g/n
Video Information: ⓘ
AMD Radeon HD 6750M - VRAM: 512 MB
iMac 1920 x 1080
System Software: ⓘ
OS X Yosemite 10.10.5 (14F1605) - Time since boot: less than an hour
Disk Information: ⓘ
ST3500418AS disk0 : (500.11 GB) (Rotational)
EFI (disk0s1) <not mounted> : 210 MB
Recovery HD (disk0s3) <not mounted> [Recovery]: 650 MB
Macintosh HD (disk1) / : 498.91 GB (453.13 GB free)
Encrypted AES-XTS Unlocked
Core Storage: disk0s2 499.25 GB Online
OPTIARC DVD RW AD-5690H ()
USB Information: ⓘ
Apple, Inc. Keyboard Hub
Apple Inc. Apple Keyboard
Apple Inc. BRCM2046 Hub
Apple Inc. Bluetooth USB Host Controller
Apple Inc. FaceTime HD Camera (Built-in)
Apple Internal Memory Card Reader
Apple Computer, Inc. IR Receiver
Thunderbolt Information: ⓘ
Apple Inc. thunderbolt_bus
Gatekeeper: ⓘ
Mac App Store and identified developers
System Launch Agents: ⓘ
[loaded] 155 Apple tasks
[running] 57 Apple tasks
System Launch Daemons: ⓘ
[loaded] 184 Apple tasks
[running] 78 Apple tasks
Launch Agents: ⓘ
[loaded] com.adobe.AAM.Updater-1.0.plist [Support]
[failed] com.adobe.ARMDCHelper.cc24aef4a1b90ed56a...plist [Support]
[running] com.brother.LOGINserver.plist [Support]
[loaded] org.macosforge.xquartz.startx.plist [Support]
Launch Daemons: ⓘ
[loaded] com.adobe.ARMDC.Communicator.plist [Support]
[loaded] com.adobe.ARMDC.SMJobBlessHelper.plist [Support]
[loaded] com.adobe.fpsaud.plist [Support]
[loaded] com.malwarebytes.MBAMHelperTool.plist [Support]
[loaded] com.oracle.JavaInstallHelper.plist [Support]
[loaded] org.macosforge.xquartz.privileged_startx.plist [Support]
User Launch Agents: ⓘ
[loaded] com.adobe.AAM.Updater-1.0.plist [Support]
[loaded] com.google.keystone.agent.plist [Support]
User Login Items: ⓘ
iTunesHelper Application (/Applications/iTunes.app/Contents/MacOS/iTunesHelper.app)
Other Apps: ⓘ
[running] com.brother.utility.NETserver.36952
[running] com.brother.utility.USBserver.36668
[running] com.etresoft.EtreCheck.59388
Internet Plug-ins: ⓘ
AdobePDFViewerNPAPI: Version: 15.010.20056 - SDK 10.8 [Support]
FlashPlayer-10.6: Version: 20.0.0.286 - SDK 10.6 [Support]
AdobePDFViewer: Version: 15.010.20056 - SDK 10.8 [Support]
QuickTime Plugin: Version: 7.7.3
Flash Player: Version: 20.0.0.286 - SDK 10.6 [Support]
Default Browser: Version: 600 - SDK 10.10
3rd Party Preference Panes: ⓘ
Flash Player [Support]
Time Machine: ⓘ
Time Machine not configured!
Top Processes by CPU: ⓘ
13% mdworker(10)
3% fontd
2% WindowServer
1% kernel_task
0% Dock
Top Processes by Memory: ⓘ
447 MB kernel_task
119 MB Finder
115 MB mdworker(10)
90 MB mds_stores
49 MB softwareupdated
Virtual Memory Information: ⓘ
1.53 GB Free RAM
2.46 GB Used RAM (1.27 GB Cached)
0 B Swap Used
Diagnostics Information: ⓘ
Feb 4, 2016, 09:49:20 PM Self test - passed
Feb 4, 2016, 06:49:09 PM /Library/Logs/DiagnosticReports/com.apple.WebKit.WebContent_2016-02-04-184909_[r edacted].cpu_resource.diag [Details]
/System/Library/StagedFrameworks/Safari/WebKit.framework/Versions/A/XPCServices/ com.apple.WebKit.WebContent.xpc/Contents/MacOS/com.apple.WebKit.WebContent
Feb 4, 2016, 05:22:50 PM /Library/Logs/DiagnosticReports/com.apple.WebKit.WebContent_2016-02-04-172250_[r edacted].cpu_resource.diag [Details]
Feb 3, 2016, 10:49:47 PM /Library/Logs/DiagnosticReports/com.apple.WebKit.WebContent_2016-02-03-224947_[r edacted].cpu_resource.diag [Details]
Feb 3, 2016, 10:33:52 PM /Library/Logs/DiagnosticReports/???_2016-02-03-223352_[redacted].cpu_resource.di ag [Details]
???