Memory not being used by 2005 instance

We have an I64 server with 12 GB of Ram. On this server we have an instance
of SQL 2000 Enterprise with max memory set to 6 GB and AWE is turned on from
SSMS. This instance seems to be running fine but is always using all the 6
GB of memory according to task manager (if I increase the max memory it will
use it). We also have an instance of SQL 2005 Enterprise with max memory set
to 3 GB and AWE is turned on from SSMS. I know you don't have to turn on AWE
on 64 bit servers but I did just in case. I hope this is enough server info
so I'll get on with the problem. The 2005 instance doesn't seem to be
running very well and from the task manager I've never seen it use more then
124 MB of memory. It seems to have way too much I\O writes and between the
two they keep the CPUs pegged. This server has 2 Itanium 2 ia64 Family 31
Model 2 Stepping 1 1596 MHz CPUs.
I talked to someone at Microsoft and they said to ignore Task Manager reading
(nice). You can tell SQL memory usage by using Performance Monitor object
SQL Memory Management counters "Target Server Memory" and "Total Server
Memory". So, unless you are a DBA and know about this, Task Manager misleads
you.
"Kenny" wrote:

> We have an I64 server with 12 GB of Ram. On this server we have an instance
> of SQL 2000 Enterprise with max memory set to 6 GB and AWE is turned on from
> SSMS. This instance seems to be running fine but is always using all the 6
> GB of memory according to task manager (if I increase the max memory it will
> use it). We also have an instance of SQL 2005 Enterprise with max memory set
> to 3 GB and AWE is turned on from SSMS. I know you don't have to turn on AWE
> on 64 bit servers but I did just in case. I hope this is enough server info
> so I'll get on with the problem. The 2005 instance doesn't seem to be
> running very well and from the task manager I've never seen it use more then
> 124 MB of memory. It seems to have way too much I\O writes and between the
> two they keep the CPUs pegged. This server has 2 Itanium 2 ia64 Family 31
> Model 2 Stepping 1 1596 MHz CPUs.
>