[ltp] Re: The mystery of missing RAM

[Bernard Tremblay]

David,

Some Onboard component do use main memory : Graphic card, network card,
Modem, ...  Onboard Graphic card in particular ...


Here are what is said on Lenovo site about the T61P :
-----------------------------------------------------
 Memory:  Lenovo notebooks announced in April 2007, or later, have a new
 64-bit architecture.

The standard memory can be expanded to 3 or 4 GB of addressable memory,
depending on whether the operating system is a 32- or 64-bit operating
system. Notebooks with the Windows Vista 32-bit or previous Windows
32-bit operating system can support up to 3 GB of addressable memory.
Notebooks with the Windows Vista 64-bit operating system can support up
to 4 GB of addressable memory.

Recommended for memory expansion are 512 MB, 1 GB, and 2 GB PC2-5300
DDR2 SDRAM 667 MHz SO DIMM. 

For systems with Intel video, it is recommended that you install memory
of the same size to enhance the performance of the Aero feature in
Microsoft Windows Vista operating systems. Example: 2 x 2 GB, 2 x 1 GB,
or 2 x 512 MB of memory. 
------------------------------------------------------

Your machine should be a 64-bit architecture if bought after april 2007
wich seems to be the case.  Thus it should be able to address 4GB of RAM
max.   But do you have and intel graphic card and 2 memory chips of 2GB
installed as recommanded ?  You could have an NVIDIA Quadro NVS 140M or
NVIDIA Quadro FX 570M graphic chipset according to Lenovo.  Wich one do
you have ?

But first : Is all the 4 GB of memory seen by the BIOS ?  

If you have an Intel graphic card X3100, I have seen it can use up to
384MB of shared memory on the main board.  I don't know what else is
onboard that eats RAM, could you provide a more extensive description of
your notebook (model number, type number, etc.) ??? 

I'm not so sure this is an issue with PAE.  

On the Lenovo site they talk about this feature:

 Intel Turbo Memory 1 GB on selected model. It works alongside the
 system RAM memory to increase efficiency of data movement between the
 processor and the HDD.

    * Saves energy as the prestored information reduces the HDD spin
    time, which saves power
    * Up to 2 times faster performance when loading frequently used
    applications
    * Up to 20 percent faster Windows Vista boot time 

Do you have Intel Turbo Memory turned on in your BIOS ?  To me it looks
it could steal 1GB of memory to use as a disk cache ...

Regards,

      BT
-- 
  Bernard Tremblay
  public@imaginasys.fastmail.fm