Internet Explorer 8 – users complained it was freezing

They were just upgraded from Internet Explorer 6.  I have two guesses why this was happening:

  1. IE6 would have been freezing as well, but because website was in it’s own browser process, the user would just close the frozen Internet Explorer, and that was that.
    and/or
  2. users now had TABBED browsing, and were using the new functionally to open websites in TABs.  A website would freeze, say due to Adobe Flash or Shockwave; and Internet Explorer 8 would freeze.

The solution I eventually found?

For up to 10 TABs, allow each TAB to run it’s own iexplore.exe process.  You can do this via a registry key called TabProcGrowth.

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.
Microsoft "We know IE!" Blog: Opening a New Tab …

TabProcGrowth is a DWORD registry entry, which you set under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Internet Explorer\Main .

For my users, I’ve set TabProcGrowth to 10.

Further reading:
We know IE! blog: Opening a New Tab may launch a New Process with Internet Explorer 8.0
HttpWatch: Seven Things You Should Known About IE 8