Where did my 512mb go?

OK, this makes no sense to me and I hope somebody can explain it to me.

This is on an Asus 1201N laptop with Atom N330 dual core and nVidia ION chipset.

OS is Windows 7 Home Premium 64 Bit.

I had 3GB RAM installed. Windows showed 2.75GB available. Fine, I can live with that. 3GB - 256MB for ION = 2.75GB usable.

I ended up with extra 2GB stick of DDR2 and decided to swap out the 1GB for a total of 4GB.

But now Windows shows 3.25GB available. I would think 4GB - 256MB for ION would give me a net of 3.75GB.

This is my question;

Where did that 512MB go and why was it not taken when I had 3GB installed?

Thank you.

 

Next, there is no way this enigmatic machine will support 8GGB of SODIMM/RAM with the present BIOS, even though the processor is an Intel Atom 64-bit N330 Dual Core CPU with the ability to use 64-bit Windows Home Premium, Professional, or Ultimate should you want to splurge and install what this computer needs to utilize its built-in CPU power, not the 32-bit OS. I installed 4GB Crucial PC-6400 800Mhz RAM, 2 x 2GB 200-pin SODIMMS, and stored the factory's 2 x 1GB OEM SODIMMs...and that's all the machine supports, period...4GB of RAM, 3.25 usable RAM for the OS, the rest for ION graphics.

I have investigated the 8GB RAM situation thoroughly, and here's the deal: there are Asus 1201N owners in the Asus Tech Support Forum who have tried 8GB of RAM, and 64-bit OS on this computer, and guess what? Yup, only 3.25GB RAM is available for the OS, end of story, the rest is held in 'Hardware Reserve' by the computer, so don't bother trying to install 8GB RAM, it just won't work...You'll just have to return 8GB of RAM, it doesn't work on the 1201N.

Asus could blow this whole controversy/problem/ability straight to Hell's Bells and come up with a BIOS fix, and we'd be stylin' and using 8GB of RAM after that, but that's what it's going to take. The latest BIOS flash on the web site is BIOS #0318--I've flashed my 1201N with that BIOS and it doesn't improve the RAM abilities, with 8GB or 4GB RAM the maximum available for the OS is 3.25GB RAM...the rest ION gets, or it is held in 'Hardware Reserve'--like the folks who sprung for 64-bit OS AND 8GB of RAM discovered.


Not my words this is from a Review so I suggest you go to the forums he is talking about and get more details. But it looks as if the rest is taken by hardware.
http://www.amazon.com/Seashell-1201N-PU17-BK-12-1-Inch-Black-Netbook/product-reviews/B002ZLOR56

 

I realize this machine only accepts 4GB and that's all I have installed.

What I would like to know is why the machine takes 256mb + 512mb away when 4GB is installed but only takes 256mb away when 3GB or less is installed? Why does "Hardware Reserve" only happen with any quantity of RAM over 3GB?

That is my question and I haven't been able to find an answer to this anywhere.

 

How much addressing does the chipset support? If only 4GB and hardware needs to use 512MB of those addresses then that leaves 3.5GB of addresses for RAM / Graphics. With 2GB of RAM there are more than enough addresses but with 4GB there are not.

Another reason could be that the chipset supports more than 4GB of addressing but there is no remapping.

I'm just guessing here as I'm totally unfamiliar with Atom products.

 

NVIDIA ION uses main memory, which is reserved at system start. I believe this is where your 512MB went....
GeForce 9400M Versus 945GC : Nvidia's Ion: Lending Atom Some Wings

- Tim

 

The system itself is reserving what appears to be 512MB of address space for device I/O. Before you had the full 4GB of memory installed it could allocate addresses for all of your RAM and all of the needed device I/Os.

 

Intel places significant restrictions on what netbook makers can make available with Atom CPUs.

Restricted memory spaces is one of those things that get cut back.

 

So realistically the maximum RAM this netbook can support is 3.5GB, not 4GB.

 

could it be a 64-bit cpu with a 64-bit OS on a 32-bit MoBo?

Jason

 

it probably went for video memory.

the more RAM you have, the more video memory some video cards use. With some limit of course.

 

GPU-Z shows 256mb for video with both 3 and 4GB.

 

What GPUz and what the BIOS will reserve for the video and other hardware is two different things.

With the higher RAM capacity, the BIOS is allowing more to be used for your gpu (if and when it is needed). To be able to do this it has to reserve it beforehand.

No mystery - just how it works.

 

So adding 1GB more of RAM to a 3GB system will cause the BIOS to take 50% of it and reserve it for additional video memory? Is that what you're saying? That seems a tad bit extreme, don't you think? Especially considering it's on a system with 1366x768 display, doesn't make much sense that Asus would want this to happen.

You happen to have a link that provides detailed information on this?

 

idk if this applies to your own problem as it's ION gen 1 and idk what your chipset is but here's a similar post to your's where it's obvious it's not additional video memory for that link.

ion/atom max memory support - NVIDIA Forums

And this link shows maximum 3.5GB supported for the particular mainboard in the link.

:: Point of View :: HOME

It would be good if nvidia made it easy to get some detailed ION specifications but all I've seen is perhaps ION gen 2 might support more than 4GB but again idk.

 

I have ION gen 1 in the 1201N.

Interesting. Looks like your links, especially the 2nd one, clears things up. The ION GPU/Chipset combo supports 3.5GB and that's it. Cut and dry now. It's not going to video, it's not going to hardware reserve, the ION simply won't support anything above 3.5GB.

What sucks is that it is intentionally handicapped. Last night I put the 8GB from my G50VT into the 1201N and the BIOS shows 8GB, Windows shows 8GB (Still 3.25GB usable.) So the hardware does see it but is factory sabotaged to ignore it. I wonder who's ultimately responsible for that. Asus, nVidia or Microsoft stipulations.