Controlling Tab Memory Usage in IE

http://blogs.msdn.com/b/askie/archive/2009/03/09/opening-a-new-tab-may-launch-a-new-process-with-internet-explorer-8-0.aspx



HKCU\Software\Microsoft\Internet Explorer\Main - TabProcGrowth (string or dword)


Tab Process Growth : Sets the rate at which IE creates New Tab processes. There are two algorithms used by Internet Explorer.


1. Context-based: By default, the context-based algorithm is used and the curve is chosen based on the amount of physical memory on the machine. In addition, the TabProcGrowth string registry value may be manually forced to:
small: Maximum 5 tab processes in a logon session, requires 15 tabs to get the 3rd tab process.
medium: Maximum 9 tab processes in a logon session, requires 17 tabs to get the 5th tab process.
large: Maximum 16 tab processes in a logon session, requires 21 tabs to get the 9th tab process.


2. The "Max-Number" algorithm: This specifies the maximum number of tab processes that may be executed for a single isolation session for a single frame process at a specific mandatory integrity level (MIC). Relative values are:
TabProcGrowth=0 : tabs and frames run within the same process; frames are not unified across MIC levels.
TabProcGrowth =1: all tabs for a given frame process run in a single tab process for a given MIC level.


Note: On Terminal Server, the default value is the integer of 1.
TabProcGrowth >1: multiple tab processes will be used to execute the tabs at a given MIC level for a single frame process. In general, new processes are created until the TabProcGrowth number is met, and then tabs are load balanced across the tab processes.


Note: that the frame process is no longer allowed to execute at low-MIC. If this is attempted, the process will exit.