I'm really, really sorry about that error in reporting on my system. I believe I meant to say a single quad-core. Is that acceptable? Listen, I don't claim to be expert on all of it, so I hope that's satisfactory for you.
As for file size, they are large, up to 2 to 3 Gb, as most digital paintings are. But that's only when I've not flattened the image. After doing so, size might be 500 Mb. This isn't relevant, since the files I'm trying to open AND save in OS 10.11.5 are exactly the same files I can so easily open and save in OS 10.6. At first, in OS 10.11, the files appear to save quickly, with just a spinning gear for a few seconds. But then, up comes the spinning color wheel for 5 to 10 minutes before the file actually opens or saves.
When I open Activity Monitor while using CS5, there doesn't appear to be anything excessive, not that an amateur like myself could know for sure. I really can't say more than that the green line or stacks of bricks isn't bouncing off the top of the appropriate window. There's very little in red, if that means anything.
Here are the results of the EtreCheck using its default settings. Even I can read "Performance: Below Average:" That comes as no surprise:
EtreCheck version: 3.0.5 (309)
Report generated 2016-09-27 13:10:47
Download EtreCheck from https://etrecheck.com
Runtime 5:20
Performance: Below Average
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:
Opening and saving files takes longer than they should
Hardware Information: ⓘ
Mac Pro (Early 2009)
[Technical Specifications] - [User Guide] - [Warranty & Service]
Mac Pro - model: MacPro4,1
1 2.66 GHz Quad-Core Intel Xeon CPU: 4-core
24 GB RAM Upgradeable - [Instructions]
DIMM 1
8 GB DDR3 ECC 1066 MHz ok
DIMM 2
8 GB DDR3 ECC 1066 MHz ok
DIMM 3
8 GB DDR3 ECC 1066 MHz ok
DIMM 4
Empty
Bluetooth: Old - Handoff/Airdrop2 not supported
Video Information: ⓘ
NVIDIA GeForce GT 120 - VRAM: 512 MB
Cinema Display 1680 x 1050
SyncMaster 1024 x 768 @ 60 Hz
System Software: ⓘ
OS X El Capitan 10.11.5 (15F34) - Time since boot: about 5 days
Disk Information: ⓘ
HL-DT-ST DVDRAM GH24NSC0 ()
WDC WD6400AAKS-41H2B0 disk2 : (640.14 GB) (Rotational)
EFI (disk2s1) <not mounted> : 210 MB
MAC (disk2s2) / : 437.48 GB (166.38 GB free)
Recovery HD (disk2s3) <not mounted> [Recovery]: 650 MB
BOOTCAMP (disk2s4) /Volumes/BOOTCAMP : 201.79 GB (148.83 GB free)
WDC WD5000AAKS-00V1A0 disk1 : (500.11 GB) (Rotational)
EFI (disk1s1) <not mounted> : 210 MB
disk1s2 (disk1s2) <not mounted> : 65.65 GB
Boot OSX (disk1s3) <not mounted> : 134 MB
DATA 1 (Disk 1 - WORKING SPACE) (disk1s4) /Volumes/DATA 1 (Disk 1 - WORKING SPACE) : 433.98 GB (201.41 GB free)
WDC WD10EALS-002BA0 disk0 : (1 TB) (Rotational)
EFI (disk0s1) <not mounted> : 210 MB
disk0s2 (disk0s2) <not mounted> : 65.65 GB
Boot OSX (disk0s3) <not mounted> : 134 MB
DATA 2 (IMAGE STORAGE & OTHER) (disk0s4) /Volumes/DATA 2 (IMAGE STORAGE & OTHER) : 934.08 GB (24.61 GB free)
WDC WD30EZRX-00D8PB0 disk3 : (3 TB) (Rotational)
EFI (disk3s1) <not mounted> : 210 MB
FAT (disk3s2) /Volumes/FAT : 125.02 GB (124.98 GB free)
IMAGE STORAGE 4th BAY (disk3s3) /Volumes/IMAGE STORAGE 4th BAY : 2.88 TB (697.33 GB free)
USB Information: ⓘ
Apple Inc. BRCM2046 Hub
Apple Inc. Bluetooth USB Host Controller
Tablet PTK-640
Realtek 802.11n NIC
APC Back-UPS ES 725 FW:802.n5.D USB FW:n5
Western Digital My Passport 0820 2 TB
EFI (disk5s1) <not mounted> : 210 MB
My Passport External Storage (disk5s2) /Volumes/My Passport External Storage : 2.00 TB (876.09 GB free)
Apple, Inc. Keyboard Hub
Mitsumi Electric Apple Optical USB Mouse
Apple Inc. Apple Keyboard
X-Rite, Inc. ColorMunki Display
Firewire Information: ⓘ
Iomega HDD unknown_device 800mbit - 800mbit max
IOMEGA HFS (disk6s1) /Volumes/IOMEGA HFS : 799.53 GB (1.54 GB free)
IOMEGA NTFS (disk6s2) /Volumes/IOMEGA NTFS : 200.68 GB (135.87 GB free)
Configuration files: ⓘ
/etc/sudoers, File size 1242 but expected 2299
/etc/hosts - Count: 15
Gatekeeper: ⓘ
Mac App Store and identified developers
Kernel Extensions: ⓘ
/Library/Extensions
[not loaded] com.FTDI.driver.D2XXHelper (1.0 - SDK 10.11 - 2016-09-03) [Support]
[not loaded] com.sonnettech.com.Sonnet-USB3-Combined-E-ChargingSupport (1.0.1 - SDK 10.9 - 2016-09-03) [Support]
/System/Library/Extensions
[loaded] com.realtek.driver.RtWlanU (1830.2.b10 - SDK 10.9 - 2016-09-03) [Support]
[not loaded] com.realtek.driver.RtWlanU1827 (1827.4.b19 - SDK 10.9 - 2016-09-03) [Support]
[not loaded] com.wacom.kext.wacomtablet (Wacom Tablet 6.3.15-3 - SDK 10.11 - 2016-09-03) [Support]
[not loaded] com.wdc.driver.1394HP (1.0.9 - 2016-09-03) [Support]
[not loaded] com.wdc.driver.USBHP (1.0.11 - 2016-09-03) [Support]
System Launch Agents: ⓘ
[not loaded] 8 Apple tasks
[loaded] 158 Apple tasks
[running] 58 Apple tasks
[killed] 14 Apple tasks
14 processes killed due to insufficient RAM
System Launch Daemons: ⓘ
[not loaded] 47 Apple tasks
[loaded] 155 Apple tasks
[running] 79 Apple tasks
[killed] 9 Apple tasks
9 processes killed due to insufficient RAM
Launch Agents: ⓘ
[running] Wlan.Software.plist (2015-10-21) [Support]
[not loaded] com.adobe.AAM.Updater-1.0.plist (2015-11-13) [Support]
[failed] com.adobe.ARMDCHelper.cc24aef4a1b90ed56a725c38014c95072f92651fb65e1bf9c8e43c37a2 3d420d.plist (2016-07-11) [Support]
[not loaded] com.adobe.CS5ServiceManager.plist (2013-10-05) [Support]
[running] com.epson.epw.agent.plist (2007-09-18) [Support]
[loaded] com.google.keystone.agent.plist (2016-07-11) [Support]
[running] com.wacom.wacomtablet.plist (2015-12-16) [Support]
[loaded] com.xrite.device.softwareupdate.plist (2013-10-22) [Support]
Launch Daemons: ⓘ
[loaded] com.adobe.ARMDC.Communicator.plist (2016-07-11) [Support]
[loaded] com.adobe.ARMDC.SMJobBlessHelper.plist (2016-07-11) [Support]
[not loaded] com.adobe.SwitchBoard.plist (2010-05-29) [Support]
[running] com.adobe.agsservice.plist (2016-08-18) [Support]
[loaded] com.bombich.ccc.plist (2012-09-17) [Support]
[running] com.easeus.dataprotectbackup.plist (2016-09-22) [Support]
[loaded] com.google.keystone.daemon.plist (2016-09-03) [Support]
[loaded] com.macpaw.CleanMyMac3.Agent.plist (2016-09-22) [Support]
[loaded] com.prosofteng.DriveGenius.locum.plist (2015-11-23) [Support]
[loaded] com.wacom.displayhelper.plist (2015-12-16)
[running] com.wdc.SmartwareDriveService.plist (2013-11-11) [Support]
[running] com.wdc.WDSmartWareService.plist (2013-11-11) [Support]
[running] com.xrite.device.xrdd.plist (2013-10-22) [Support]
User Launch Agents: ⓘ
[loaded] com.adobe.AAM.Updater-1.0.plist (2010-05-29) [Support]
[loaded] com.macpaw.CleanMyMac3.Scheduler.plist (2016-09-22)
User Login Items: ⓘ
GrowlHelperApp Application (/Library/PreferencePanes/Growl.prefPane/Contents/Resources/GrowlHelperApp.app)
EEventManager Application (/Applications/Epson Software/Event Manager.app/Contents/Resources/Assistants/Event Manager/EEventManager.app)
Stickies Application (/Applications/Stickies.app)
CleanMyMac 3 Menu Application (/Applications/CleanMyMac 3.app/Contents/MacOS/CleanMyMac 3 Menu.app)
ColorMunki Display Application (/Applications/ColorMunki Display.app)
DiskWarriorDaemonStarter Application (/Applications/DiskWarrior.app/Contents/Helpers/DiskWarriorStarter.app)
DRWTray Application (/Applications/EaseUS Data Recovery Wizard.app/Contents/MacOS/DRWTray.app)
EEventManager Application (/Applications/Epson Software/Event Manager.app/Contents/Resources/Assistants/Event Manager/EEventManager.app)
Internet Plug-ins: ⓘ
Google Earth Web Plug-in: 6.1 (2016-04-10) [Support]
Default Browser: 601 - SDK 10.11 (2016-06-23)
WacomTabletPlugin: WacomTabletPlugin 2.1.0.6 - SDK 10.9 (2015-12-16) [Support]
AdobeAAMDetect: AdobeAAMDetect 1.0.0.0 - SDK 10.6 (2015-11-13) [Support]
AdobePDFViewerNPAPI: 15.017.20053 - SDK 10.11 (2016-08-17) [Support]
LogMeIn: 1.0.990 - SDK 10.7 (2014-10-08) [Support]
Silverlight: 5.1.41212.0 - SDK 10.6 (2016-04-10) [Support]
QuickTime Plugin: 7.7.3 (2016-06-23)
LogMeInSafari32: 1.0.990 - SDK 10.7 (2014-10-08) [Support]
PepperFlashPlayer: 23.0.0.162 - SDK 10.9 (2016-09-13) [Support]
iPhotoPhotocast: 7.0 (2010-05-27)
AdobePDFViewer: 15.017.20053 - SDK 10.11 (2016-08-17) [Support]
JavaAppletPlugin: 15.0.1 - SDK 10.7 (2012-07-06) Check version
User internet Plug-ins: ⓘ
Unity Web Player: UnityPlayer version 2.6.1f3 (2010-07-24) [Support]
Safari Extensions: ⓘ
Awesome Screenshot - Diigo - http://www.diigo.com/ (2012-01-17)
Ka-Block! - David Graham & Josh Peek - http://kablock.com (2016-09-05)
TinEye - TinEye - https://tineye.com (2015-10-21)
Print Plus - slicefactory (2013-05-18)
Duplicate Tab Button - Thiemo Gamma - http://thiemo.ch/ (2013-05-18)
Clean Links for Google - Dennis Umetzu - http://www.umetzu.com (2016-02-19)
Add To Amazon Wish List - Amazon.com - https://www.amazon.com/wishlist?ref=cm_wl_saf_ext (2013-01-18)
Ultimate Status Bar - Karl Dearden - http://ultimatestatusbar.com/ (2015-10-15)
My eBay Manager - eBay Inc (2015-10-15)
WOT - WOT Services Ltd - http://www.mywot.com/ (2016-04-22)
Dictionary - slicefactory - http://www.slicefactory.com (2012-01-17)
Asym - Asymmetrica Labs - http://asym.co/ (2016-08-19)
ResizeMe - Aaron Holland - http://aaronholla.webs.com (2015-10-15)
Translate - SideTree.com - Apps for Mac and Web - http://SideTree.com/extensions.html#Translate (2015-10-15)
Awesome Screenshot - Diigo - http://www.diigo.com/ (2016-02-19)
3rd Party Preference Panes: ⓘ
Growl (2016-04-10) [Support]
WacomTablet (2016-06-03) [Support]
Time Machine: ⓘ
Skip System Files: NO
Auto backup: NO - Auto backup turned off
Volumes being backed up:
MAC: Disk size: 437.48 GB Disk used: 271.10 GB
Destinations:
STORAGE 2 [Local]
Total size: 0 B
Total number of backups: 0
Oldest backup: -
Last backup: -
Size of backup disk: Too small
Backup size 0 B < (Disk used 271.10 GB X 3)
Top Processes by CPU: ⓘ
3% WacomTabletDriver
3% kernel_task
3% WindowServer
1% fontd
1% Adobe Photoshop CS5
Top Processes by Memory: ⓘ
16.32 GB Adobe Photoshop CS5
1.34 GB kernel_task
492 MB softwareupdated
295 MB Google Chrome Helper(2)
172 MB mds_stores
Virtual Memory Information: ⓘ
562 MB Free RAM
23.00 GB Used RAM (3.61 GB Cached)
8.77 GB Swap Used
Diagnostics Information: ⓘ
Sep 26, 2016, 03:16:11 PM /Library/Logs/DiagnosticReports/Adobe Photoshop CS5_2016-09-26-151611_[redacted].cpu_resource.diag [Details]
/Applications/Adobe Photoshop CS5/Adobe Photoshop CS5.app/Contents/MacOS/Adobe Photoshop CS5
Sep 24, 2016, 06:57:40 PM /Library/Logs/DiagnosticReports/softwareupdated_2016-09-24-185740_[redacted].cr ash
/System/Library/CoreServices/Software Update.app/Contents/Resources/softwareupdated
Sep 19, 2016, 04:34:46 PM /Library/Logs/DiagnosticReports/Kernel_2016-09-19-163446_[redacted].panic [Details]
Thank you for your time and courtesy.