Well my storage machine build is underway.  I just installed WHS over the weekend and found something that irritated me.  This of course would be that I have 4GB of memory in this system and it only shows 3.25GB of usable memory (ohh the plot thickens). 

I have already solved this mystery (I think), and I just wanted to inform others so they don't make the same mistake when choosing hardware as I did.  This sounds like a 32bit vs. 64bit issues, such as the other topic on 4GB of memory in Vista that I posted, but its not.  For this machine I had picked out a Foxconn G31MX-K (http://www.newegg.com/Product/Product.aspx?Item=N82E16813186135), which supports 4GB of memory.  So I figured I was in the butta zone, and wouldn't have any issues once I got a 64bit OS installed, HA!

Due to the fact that this board ONLY supports a total of 4GB of memory, it puts you in the same boat as a 32bit OS.  I can have 4GB of memory and the BIOS sees it all, but once we get into the OS I am restricted to 4GB of TOTAL memory for my system.  From my understanding if I would have picked up a board that supported more than 4GB of memory, say 8GB, I wouldn't have this issue at all.

For the non-believers I installed Win XP Pro 64bit on this system also, and I had the same issue. 


So in summary:
- Motherboard supports 4GB of memory.
- BIOS sees all 4GB of memory.
- BIOS was updated as of yesterday (10/05/08).
- No option in the BIOS for "remapping" of memory (this was an issue with some HP boxes, that once turned off would allow them to have 4GB of usable memory).
- WHS only has 3.25GB of usable memory.
- Win XP Pro 64bit only has 3.25GB of usable memory.

weird!! when i first installed server 2003 i had the same issue but microsoft had a few patches that fixed it and then the OS saw all 4 gig.

Yeah but what motherboard did you use and did the board itself support more than 4 gigs of RAM??  I don't think it is so much the OS but more the motherboard that is limiting him.

Dave, both installs were patched with everything that was available as of yesterday (10/05/08).  As Rathe mentioned, I believe its down to a hardware limitation and I wanted to make others aware so they didn't do what I did.  I hadn't found any documentation or anything telling me this before I purchased the board, but now that I see the problem I found multiple forum threads of people having the same issue that I am running into, and everyone is pointing to the limitation of their motherboards.  

I knew that my board supported 4GB, which I looked into before purchasing it, but I didn't know that my MAX was 4GB.  After I read a few of the forum threads, I went to Foxconn's website and sure enough my MAX supported memory was 4GB.  I was hoping a BIOS update would fix the issue, but no dice.

The weird thing is, is that this motherboard has an integrated video and a minimal amount of other devices plugged into it, so I would really like to know where the other 750MB of memory is going.  I have a feeling that I won't find an answer to this part of the mystery.  

This is from an article on how to actually use 4GB of memory in Vista 32-bit, but I think the information is still relevant to this discussion: 

http://support.microsoft.com/kb/929605/en-us

Note When the physical RAM that is installed on a computer equals the address space that is supported by the chipset, the total system memory that is available to the operating system is always less than the physical RAM that is installed. For example, consider a computer that has an Intel 975X chipset that supports 8 GB of address space. If you install 8 GB of RAM, the system memory that is available to the operating system will be reduced by the PCI configuration requirements. In this scenario, PCI configuration requirements reduce the memory that is available to the operating system by an amount that is between approximately 200 MB and approximately 1 GB. The reduction depends on the configuration.

This would explain my situation.  I would imagine that if I research the chipset on my motherboard that it only supports 4GB, as I know the CPU supports more;  the above would then apply.

Quote from: The Doctor on October 06, 2008, 01:07:34 PM

Very odd cause my media center board only supports 4GB and I see all of it.

Can it use all 4GB?  Because I can see all 4GB in Vista, but I cant use all of it.

Are you referring to what Vista uses in Shard video memory?

maybe you should just get another mobo.  one that supports 8 gig then maybe theres a sale of such board on newegg.  sell that one ebay or something.

well I have winxp 32bit and my task manager says i have 3406252 of mem i guessing thats about 3.2gig.  hmm i thought xp only supported 2 gig of mem.

well I have winxp 32bit and my task manager says i have 3406252 of mem i guessing thats about 3.2gig.  hmm i thought xp only supported 2 gig of mem.

No XP 32 bit will go up to 4 GB but it subtracts reserved memory for PCI channels etc.  I have 3 gigs of RAM in my system right now.  Never saw the need to go to 4 as I won't get much more than I currently have.