Dammit. I think I just wasted $20 on a 2 GB SoDIMM. 4 GB seen as 3.12 GB.

[Eug]

And no, it's not a 32-bit OS. I'm running Win 7 64-bit on an Atom machine - Acer Revo R3610. It has an Atom 330 dual 1.6 GHz, with integrated nVidia ION.

According to CPU-Z:

Motherboard
Manufacturer: Acer
Model: FMCP7A-ION-LE
Chipset: NVIDIA ION Revision B1
Southbridge: NVIDIA ION Revision B2
LPCIO: ITE IT8720

BIOS
Brand: American Megatrends Inc.
Version: P01-A4
Date: 11/03/2009

It's currently set to 128 MB for the integrated graphics, which gives me 2.87 GB with 3 GB installed, and 3.12 GB with 4 GB installed.

I assume there is no way to correct this and that it is simply a chipset limitation. Is that correct? There are no memory remapping settings in the BIOS that I can see. I only see something for graphics memory allocation. Which reminds me... 128 GB ought to be enough right? No gaming. Just Windows Aero and HD video playback, on a single HDMI-connected monitor. What about if I go dual-monitor? Would 256 MB be necessary? (There are settings all the way up to 512 MB.)

Oh well, I may as well leave the 2x2 GB SoDIMM in, as it potentially gives me a small boost from dual-channel and an extra 256 MB of space. Better than nothing I suppose.

 

[Ketchup]

That's weird. So just to be clear, it shows 128 MB for integrated graphics after your upgraded the memory?

Yeah, chipset limitation is the only thing I can think of. Nvidia's page kinda skips over that section:

http://www.nvidia.com/object/picoatom_specifications.html

but the Acer page says it should go up to 4:

http://panam.acer.com/acerpanam/desktop/2009/acer/aspire/AspireR3610/AspireR3610sp2.shtml

Is there another setting for video memory in the nvidia application? I have never seen one, but I have never had an ION chip either.

 

[Eug]

The BIOS has a setting for graphics memory allocation. I have it currently set to 128 MB and that leaves me with 3.12 GB memory available to Windows 7. Going to 256 MB doesn't seem to make any difference for the graphics with my usage. However, if I set it to 256 MB, then my usable memory for Windows drops to 3.0 GB.

It seems the RAM in my system is seen as 3.25 GB, minus whatever you set for the graphics memory, hence 3.12 GB currently.

Some Googling brings me here:

Atom-based desktop recognizes 3GB of RAM out of 4GB

If you have 4GB of Random Access Memory (RAM) installed in your Aspire Revo R3600 or R3610, the operating system recognizes it as only 3GB. This is not due to any software limitations, but to the architecture of the Atom processor.

CAUSE

Due to its design, the Atom processor can address up to 4 GB of RAM. Parts of the memory will be assigned to hardware resources during the start-up of the system, making this memory invisible for the Operating System.

SOLUTION

This is expected product behaviour due to its design, and it does not indicate a product failure or bug.

MORE INFORMATION

The System missing memory is used in the following way:

256 megabytes (MB) is assigned as video memory.
A total of 512 MB is used for PCI hardware resources.
256 MB is dedicated to PCI Express hardware resources.

Is that just BS, and it's really just a chipset limitation? Cuz if I have 3 GB installed, I still see 2.87 GB (after 128 MB is allocated to graphics). If the above were true, I'd only see 2.0 to 2.12 GB.

 

[Ketchup]

Sounds like there is a legitimate chipset limitation someone is explaining with BS. So why does every other computer show us the correct amount of memory, but this one can't because of a mysterious "512 MB is used for PCI hardware resources" that no other computer uses? Did it use this before you added the memory? I am guessing no.

 

[MagnusTheBrewer]

Sorry, didn't mean to derail the thread.

 

[Eug]

Given the limitations of an Atom processor, I mean no offense but, isn't this like ricing out a Chevy Sonic?

Not at all. It's about making it more usable by avoiding paging to disk. Running an Atom machine with insufficient RAM just makes it even slower. Atom + 2 GB means bumping up to the RAM limits quite frequently even with just simple usage. Atom + 3 GB is OK though. Atom + 4 GB might have been better had I been able to make use of all the RAM but in this setup, it maxes out at 3.25 GB (including graphics RAM).

P.S. I already have an SSD in the thing, which is an absolute necessity. Atom + laptop HD = extremely slow. Atom + SSD makes it OK.

To use a crappy car analogy:

Atom + laptop platter drive + low RAM = Chevy Sonic with wooden wheels = basically unusable
Atom + SSD + lots of RAM = Chevy Sonic with real wheels and proper rubber tires = usable but not fast

Note: This is a "net top" computer mounted to the back of a monitor. No "desktop" part to it at all.

Sounds like there is a legitimate chipset limitation someone is explaining with BS. So why does every other computer show us the correct amount of memory, but this one can't because of a mysterious "512 MB is used for PCI hardware resources" that no other computer uses? Did it use this before you added the memory? I am guessing no.

Exactly.

3 GB + 128 MB allocated to video = 2.87 GB
4 GB + 128 MB allocated to video = 3.12 GB

They should have just said it was a chipset limitation, and been done with it, instead of claiming it can make use of 4 GB RAM. If you look in the specs, they state the system can handle 4 GB RAM, which is why I bought the extra RAM.

Oh well, it's only $20. That's less than what I spent today on our shawarma dinner. And I still get an extra 256 MB over what I had before. So maybe I only wasted $15 actually.