Windows XP XP Pro 64 Bit - Kernel settings discovery questions

[vizion]

Hi
I am hoping someone can point me in the right direction.

I have windows XP pro x64 bit installed and running fine using 4GB ram and
am about to upgrade to 8GB. The system is mainly used for processing
photographs using Photoshop. I have recently upgraded to CS4 which supports XP x64 bit and I need all the memory I can have on board.

I have now been told (but have not had that confirmed) that the memory remap feature should have been enabled, through the bios, prior to installing the OS to ensure that XP x64 would support more than 4GB.

Although the bios memory remap feature is currently enabled I cannot remember whether I did that prior to installing the OS or afterwards.

I have had some problems in upgrading the memory to 8GB mainly, I believe,
to having been supplied with DRAM that is not suitable for the mobo when all the slots are used. I am about to replace the DRAM but want to be sure whether the OS is ready for 8GB. Incidentally the mobo is an Asus P5W De Luxe which I now know to be very picky about memory and timings when 8GB is installed. I now know the memory I have needs to be replaced with sticks that comply with JEDEC and my current sticks are OCZ2G8004GK which do not!

I need to rule out an ill configured kernel as a potential source of memory difficulties when running 8GB of dram

My questions are:
1. How can I check whether the OS has been installed in a way that ensures
support for >4GB? I was told that there is some setting for the kernel.

2. If not how can I update the kernel to recognise the current bios setting
which is memory Remap [Enabled] I would rather not have to do a reinstall of
the OS unless I really have to!!

Thanks in advance

David

Photographic Artist

 

[muckshifter]

There are three requirmewnts to using a 64bit OS

The MB must be 64bit compliant and support at least 8 GB of address space ...

Chipsets that have this capability include the following: Intel 975X Intel P965 Intel 955X on Socket 775, or newer.

Chipsets that support AMD processors that use socket F, socket 940, socket 939, or socket AM2, or newer. These chipsets include any AMD socket and CPU combination in which the memory controller resides in the CPU.

The BIOS must support the memory remapping feature. The memory remapping feature allows for the segment of system memory that was previously overwritten by the Peripheral Component Interconnect (PCI) configuration space to be remapped above the 4 GB address line. This feature must be enabled in the BIOS configuration utility on the computer.
​

No standard terminology is used in documentation or in BIOS configuration utilities for this feature. Therefore, you may have to read the descriptions of the various BIOS configuration settings that are available to determine whether any of the settings enable the memory remapping feature.


The CPU must support the x64 instruction set.

An x64 (64-bit) version of Windows must be used.


If you wanna play with the kernel, go get Linux.

 

[vizion]

There are three requirmewnts to using a 64bit OS













The MB must be 64bit compliant and support at least 8 GB of address space ...

Chipsets that have this capability include the following: Intel 975X Intel P965 Intel 955X on Socket 775, or newer.







Chipsets that support AMD processors that use socket F, socket 940, socket 939, or socket AM2, or newer. These chipsets include any AMD socket and CPU combination in which the memory controller resides in the CPU.

The BIOS must support the memory remapping feature. The memory remapping feature allows for the segment of system memory that was previously overwritten by the Peripheral Component Interconnect (PCI) configuration space to be remapped above the 4 GB address line. This feature must be enabled in the BIOS configuration utility on the computer.






​

No standard terminology is used in documentation or in BIOS configuration utilities for this feature. Therefore, you may have to read the descriptions of the various BIOS configuration settings that are available to determine whether any of the settings enable the memory remapping feature.








The CPU must support the x64 instruction set.

An x64 (64-bit) version of Windows must be used.


If you wanna play with the kernel, go get Linux.

It looks as though I confused you.
I thought my question had been made clearly enough -- but obviously not.
I said

I need to rule out an ill configured kernel as a potential source of memory difficulties when running 8GB of dram

Thanks for replying but what I said needed to know was based on an understanding of the requirements for 64bit computing but a lack of knowledge about how win xp pro x64 installs its kernel. I need to know:

1. How can I check whether the OS has been installed in a way that ensures support for >4GB? I was told that there is some setting for the kernel.

I must have confused you because this is really a way of asking a two part question:

Part 1.when the kernel is being compiled upon installation of the OS, is it compiled differently depending upon the then current bios setting for memory mapping (assuming an x64 instruction set)?.

(My understanding is that when xp x64 and vista x64 is being installed the windows installer reads the bios to help determine how it should configure the kernel which it is about to install. I cannot find any documentation that tells me what it does if it finds the bios not to have been configured to enable memory mapping.)

Part 2. If it is compiled differentially how can one find out which way it was compiled?

My second question was:

2. If not how can I update the kernel to recognise the current bios setting which is memory Remap [Enabled] I would rather not have to do a reinstall of the OS unless I really have to!!

Which I could have been expressed better by saying:

2. If it was compiled in a way that inhibits the use of >4GB DRAM is it possible to correct the situation without doing a complete reinstall?
(This would only be necessary if the kernel configuration was fixed on the assumption that any change to bios memory mapping from disabled to enabled should necessitate a complete reinstall. However that is the kind of crazy thinking that would be typical at MS$ stable !!)

Regarding playing with kernels

If you wanna play with the kernel, go get Linux.

I prefer playing with FreeBSD - it is faster, more configurable and much better at networking than linux which is only a cut down desltop version of unix. I love my freebsd servers!! (Incidentally they run linux emulation transparently at the same time as freebsd)

David Southwell ARPS
Photographic Artist

 

[muckshifter]

I'd love to see how you re-compile the Windows Kernel ... but not really.

So yeah, I'm confused as to what you expect XP to be able to do if it don't "see" a default 64bit hardware setup.

As far as I see it, which ain't very far, your system meets min standards to install XP64 bit with 128GB ram ... your MB on the other hand can only use 8GB and by your own admission needs careful consideration to what ram is used.


Any 64bit OS needs 3 things ...

A 64bit OS
A MB that is 64bit aware/compatible/correct chipset
A 64bit CPU

... the limiting factor to "consumers" is memory at 128GB max.

With the right hardware and configuration 64bit OS can theoretically recognise and utilize up to 16 Terabytes of Ram.

 

[vizion]

I'd love to see how you re-compile the Windows Kernel ... but not really.

So yeah, I'm confused as to what you expect XP to be able to do if it don't "see" a default 64bit hardware setup.

As far as I see it, which ain't very far, your system meets min standards to install XP64 bit with 128GB ram ... your MB on the other hand can only use 8GB and by your own admission needs careful consideration to what ram is used.


Any 64bit OS needs 3 things ...

A 64bit OS
A MB that is 64bit aware/compatible/correct chipset
A 64bit CPU

... the limiting factor to "consumers" is memory at 128GB max.

With the right hardware and configuration 64bit OS can theoretically recognise and utilize up to 16 Terabytes of Ram.

I suggest we need to add at least a fourth consideration.

It is definite that a 64bit Windows OS will run as 64bit and support up to 4GB of ram.

However a x64 bit OS which does not have the ability to take advantage of memory remapping will be limited to 4GB! Therefore the fourth consideration, if you need more that 4GB, is to check whether the OS kernel has memory remapping support when it is turned on in the bios.

So far I have not found a way of checking that independently -- one of the purposes of this thread is to try and find someone who know how to do that. Maybe someone else will no know!!! (Do not say try running it on a system with more than 4GB because that does not rule out other possible causes of failure!)

Ny two pennorth!!