Large Memory Pages

Houdini will use so-called large memory pages if they are provided by the operating system. Depending on the hash table size the speed improvement may be between 5% and 10%.
To enable this feature in Windows, you need to modify the Group Policy for your account:

1. Run: gpedit.msc (or search for "Group Policy")
2. Under "Computer Configuration", "Windows Settings", "Security Settings", "Local Policies" click on "User Rights Assignment"
3. In the right pane double-click the option "Lock Pages in Memory"
4. Click on "Add User or Group" and add your account or "Everyone"
5. You may have to logoff or reboot for the change to take effect

You'll also need to run your chess GUI with administrative rights ("Run as Administrator") or disable UAC in Windows.
Very often large pages will only be available shortly after booting Windows. After a while the Windows memory becomes too fragmented for large page allocation, and Houdini will fall back to standard memory page usage.