XP Pro 32bit on X99 with 16GB of Ram, only 912MB of RAM available, why?

[ruthan]

Hello,

i have this X99 MB -MSI X99S SLI PLUS with Windows XP SP3 32bit + Geforce 7950 GT PCI-E - all updates and 2x 8GB (3000 Mhz, Dual Channel) of DDR4 Memory, Aida64 see - 2 stick

In Windows i see only 912 MB of available of RAM, im used to 3.* GB or 2.9 or something like that what could be wrong?

  Part of cd image was some Firadisk driver i have such device in device manager. Im using IDE mode of Sata devices and some null drivers for unknow devices - but problem with RAM was right after installation.
  How to fix it?

  BTW im still looking for Intel 218-V driver for XP, sound and GPU acceleration is working so, if i fix RAM problem and LAN driver - XP for retro gaming could be great with this board.

Edited July 4, 2017 by ruthan

[HarryTri]

21 hours ago, ruthan said:

3000 Mhz

There must be a mistake here. Also how much memory does the Windows XP detect totally?

[ruthan]

I googled, i looks like problem with memory range for some device, is too huge, but i dont know how to change it. Other people had same problem. When i boot in Linux 64bit i see all 16 GB of RAM.
I also tested Win 7 64bit - all ok and  other fully image of WinXP 32 image transfer - same problem - cca 920 MB RAM.

  I know that XP is not supported, but this board is XP 32 bit unfriendly i dont know if other X99 could be better (more that 1 GB of RAM).

https://superuser.com/questions/89997/windows-only-sees-768-mb-ram-out-of-4-gb

https://support.microsoft.com/en-gb/help/978610/the-usable-memory-may-be-less-than-the-installed-memory-on-windows-7-b
Similar problem of other user here with Asrock board and X99 and Windows 2000 - 1.5 GB of Ram, from 4 GB:

Here you can see, that memory address range for one BUS PCI is huge. I dont know maybe is because i disable lost of integrated devices for smoother install, i checked bios, there is no setting which could affect this. Update i just checked Win 7 64bit device manager memory range for this device is same - it could be Bios design flaw - nobody care about 32 OS usage, i wonder if Windows 7 32 or Windows 10 32bit would have more RAM available?

Update: I have tried 3 GPus and Windows 7 32 bit - its the same.

Edited July 7, 2017 by ruthan