Citrix User with large monitors or three monitors cannot move applications

The resolution supported by the citrix servers needs to be increased beyond the settings allowed in the Citrix Access Management Console. This requires calculating the user requirements and modifying the registry on all citrix servers.

X-Width of the ICA session window
Y- Height of the ICA session window
Z-Color Depth of the ICA session window (1-8 bit, 2-16 bit, 3-24 bit)
M-Session Graphics Memory Required

For example: for a 1024x768x24 bit session M = 1024*768*3 = 2,359,296 bytes

1. Launch the Access Management Console and edit the server properties for each server that needs adjusted. Visit the Display settings page and deselect Use farm settings. Without this step. IMA overrides any change made to thinwire’s MaxLVBMem parameter in the registry with the appropriate farm setting.

2. Determine the MaxLVBMem parameter from the maximum session size and depth.

If X,Y represent the dimensions of bounding rectangle for all monitors, and D is the maximum pixel bit depth, then MaxLVBMem is given by:

X * Y * D / 8

3. Adjust Window’s SessionPoolSize parameter as needed to accommodate increased LVB memory requirements.

MaxLVBMem should ideally consume no more than 35-40% of the system’s allocated SessionPoolSize. If more than 40% of SessionPoolSize would be consumed, then adjust the SessionPoolSize parameter upward in the system registry and restart the system.

SessionPoolSize parameter is held in a DWORD value named SessionPoolSize in system registry at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management. It is expressed in megabytes. Microsoft recommends raising this setting in increments of 16MB.

Default SessionPoolSize for x86 systems is either 16 MB or 32 MB depending upon how much memory your system is configured with. Default SessionPoolSize for x64 systems is 64 MB.

Recommend: create a DWORD registry value named SessionPoolSize in the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management registry key and set decimal value to 64

The system must be restarted for the setting change to take affect.

4. Launch regedit and go to:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Terminal Server\Wds\icawd\thin16.

5. Edit the value named MaxLVBMem and increase it to the value derived in step 1.
Recommend: set MaxLVBMem to Decimal value of 27,648,000.

Lock the settings so Citrix Management Console doesn't override these registry settings.

Right-click the thin16 key and click Permissions from the context menu.

Click the Advanced button.

Click the Add button.

Type SYSTEM in the Enter the object name to select field and click OK.

Select the Deny check box for Set Value.

(Without this step, IMA overrides any change made to MaxLVBMem parameter in the registry with the appropriate farm setting.)

12. Click OK.

13. Click Yes when you see the security warning.

14. Click OK twice.

15. Under Display Settings in Citrix Access Management Console, UNCHECK Use Farm Settings

NOTE: Citrix 4.5 needs to have Rollup 3 for these entries to apply properly.

Related Citrix Articles:
CTX114497, CTX115637, CTX105022