I was having similar issues, however turning off the Suitcase Fusion 4 plug-in did not entirely correct the performance issues with Photoshop CS6. As this was also causing Photoshop to crash I pulled up the Event viewer for Windows 8. Within the Event Viewer’s Windows Logs/Applications were multiple “Application Errors” for Photoshop CS6 and all pointed at the same file “CoreFoundation_v11x64.dll”. This file is located at C:\Program Files (x86)\Extensis\Suitcase Fusion 4\CoreFoundation_v11x64.dll and is apparently a product of Apple Computer.
On renaming that dll to “CoreFoundation_v11x64.dll_OLD” Photoshop CS6 returned to normal operation.
I have put in a support email to Extensis because I have no idea how disabling the above dll is/will affect Suitcase Fusion 4.
All I know is that Photoshop is more mission critical for my work while Suitcase is more of a helper app, if I have to pick between the two Suitcase is gone.
Bellow is one of the error reports from the Windows Event Viewer, there were lots of these present.
Log Name: Application
Source: Application Error
Date: 3/8/2013 6:58:46 PM
Event ID: 1000
Task Category: (100)
Faulting application name: Photoshop.exe, version: 22.214.171.124, time stamp: 0x5022da9d
Faulting module name: CoreFoundation_v11x64.dll, version: 126.96.36.199, time stamp: 0x50c790eb
Exception code: 0xc0000005
Fault offset: 0x0000000000038c93
Faulting process id: 0x674
Faulting application start time: 0x01ce1c58b0a32e61
Faulting application path: C:\Program Files\Adobe\Adobe Photoshop CS6 (64 Bit)\Photoshop.exe
Faulting module path: C:\Program Files (x86)\Extensis\Suitcase Fusion 4\CoreFoundation_v11x64.dll
Report Id: 1c8bf34a-884c-11e2-be90-bc5ff4498d0b
Faulting package full name:
Faulting package-relative application ID:
C:\Program Files\Adobe\Adobe Photoshop CS6 (64 Bit)\Photoshop.exe
C:\Program Files (x86)\Extensis\Suitcase Fusion 4\CoreFoundation_v11x64.dll