Re: Only 3.2G ram out of 4G seen in an i386 box

From: gmu 2k6
Date: Wed Aug 09 2006 - 02:49:28 EST

On 8/8/06, David Schwartz <davids@xxxxxxxxxxxxx> wrote:

> Replying to Thomas Stewart:

> > Hi,
> > I have a Dell Optiplex GX280, a Pentium 4 with an Intel chipset. It has
> > 4G of ram. The problem is I can only see 3.2G, even tho the bios reports
> > 4G.

> Chipset issue. Some Intel chipsets are doing strange things with memory
> map. They call this "design flaw" but not offered free replacements
> yet, so, for example, on SE7221BK1E you can't use more than 3 gigs.

It is quite funny to read Intel's technical note on this, as they try to
make it seem like they're blaming the operating system. For example:

When the Intel E7221 chipset is populated to its maximum memory capacity of
4 GB (Giga Bytes), the Operating System (OS) may report a significantly
lower amount of available memory.

Yeah, that stupid operating system.

These requirements may reduce the addressable memory space available to and
reported by the Operating System. These memory ranges, while unavailable to
the OS, are still being utilized by subsystems such as I/O, PCI Express and
Integrated Graphics and are critical to the proper functioning of the

Use of Available memory below 4 GB by system resources is not specific to
Intel chipsets, but rather a limitation of existing PC architectures and
current limitations of some 32-bit operating systems. Some 32-bit operating
systems may not be capable of recognizing greater than 2 GB of memory. This
issue potentially impacts any chipset with 4GB maximum memory configuration.

Intel has addressed this from a hardware perspective in future platforms,
anticipating that future Operating Systems will provide greater than 4 GB of
memory support.

Last but not least, their solution.

Corrective Action / Resolution
Intel Server Board SE7221BK1-E system BIOS will be updated to properly
indicate the following information screens augment memory configuration
characteristics for the Intel Server Board SE7221BK1-E and Intel Server
Platform SR1425BK1-E customers.
Total physical memory populated in the system
Total memory dedicated to motherboard resources
Total memory reported as available to the operating system
This information will align to the INT15h E820h standard that BIOS uses to
communicate memory usage to the operating system. This BIOS feature will
clarify the memory subsystem support and usage for the end user.

Are these technical notes supposed to be so funny?


I guess this is all related to older Intel chipsets, right? I mean the
chipset *75X something I'm going to have in the new box I will get
soonish will support up to 8 GiB. I hope it does not mean that it will
be capped at 7.4GiB although I will only have 4GiB installed for now.
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at