I have an Abit IL9 Pro motherboard. I've been frustrated, because even though I have Windows 7 x64, I've been limited to 3.12GB of RAM. The BIOS would output that it only detected 3200mb during the post message.

So I decided to update my BIOS. Everything updated successfully, and the post message now correctly states that 4096mb of RAM is detected. The problem is that there is a new message as well:

DRAM frequency has been downgraded, canse 50 Ohm ODT unsupported

Now Windows 7 states that there is only 2.87GB of RAM usable (4.00GB total), which is worse than when I started!

I am using 2 sticks of PC2-4200 RAM (533 mhz, 2GB per stick, here is a link to the specific model). I've tried running the computer with only 1 stick in at a time, and I've tried using both sets of ports for the RAM on the motherboard, but no matter what I do the message doesn't go away.

What can I do to get full use of my RAM and have my system running as it should?


Look through your BIOS settings for 'memory remapping'. Turn it on.

| improve this answer | |

It has to do with other hardware in the system using some of that memory address space, here is an article about Vista, but hold true for W7 also. This is a limitation in 32bit or 64bit Windows.

This behavior is the expected result of certain hardware and software factors.

Various devices in a typical computer require memory-mapped access. This is known as memory-mapped I/O (MMIO). For the MMIO space to be available to 32-bit operating systems, the MMIO space must reside within the first 4 GB of address space.

For example, if you have a video card that has 256 MB of onboard memory, that memory must be mapped within the first 4 GB of address space. If 4 GB of system memory is already installed, part of that address space must be reserved by the graphics memory mapping. Graphics memory mapping overwrites a part of the system memory. These conditions reduce the total amount of system memory that is available to the operating system.

The reduction in available system memory depends on the devices that are installed in the computer. However, to avoid potential driver compatibility issues, the 32-bit versions of Windows Vista limit the total available memory to 3.12 GB. See the "More information" section for information about potential driver compatibility issues.

If a computer has many installed devices, the available memory may be reduced to 3 GB or less. However, the maximum memory available in 32-bit versions of Windows Vista is typically 3.12 GB.


| improve this answer | |
  • If this is the issue, then why would updating my bios decrease the amount of ram available? And it doesn't explain the bios error. – Samusaaron3 Oct 1 '11 at 22:35
  • @Samusaaron3: You should check that the "Map Memory Hole" setting might have changed when you flashed the BIOS. – surfasb Oct 1 '11 at 22:37
  • Unfortunately there is no such setting. My bios is pretty crappy. The only things related to memory that I can modify are the frequency (auto, 533, or 667) and voltage adjustment (+0.1, +0.15 etc.). Nothing about memory mapping or timing. – Samusaaron3 Oct 1 '11 at 22:47
  • 1
    If there is a load defaults in the bios try that. – Moab Oct 1 '11 at 23:47
  • I have tried multiple sets of settings, and have also cleared my CMOS multiple times. – Samusaaron3 Oct 1 '11 at 23:50

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.