<p>I've noticed that SQL Server 2005 x64 does not seem to lock pages into memory the same way SQL Server 2000 did.  In 2000 I could easily see from task manager that SQL had locked 8GB of ram with AWE.  I'm fairly certain I've got 2005 setup in an equivalent way.</p>

<p>Is this a normal x64 difference or am I forgetting a crucial setup option?</p>

SQL Server 2005 x64 certainly doesn't need, or use, AWE; AWE is only to allow it to use > 4GB on 32 bit systems.
You
can
use the old lock-pages-in-memory trick, but as this KB shows (
http://support.microsoft.com/kb/918483
): "Note For 64-bit editions of SQL Server 2005, only SQL Server 2005 Enterprise Edition can use the Lock pages in memory user right."