Motherboards with memory remapping for 64bit OSes

[delizseemack]

Hello,

I'm looking for a list of mainstream motherboards that supports some kind of memory remapping features for 64bits OSes so that memory mapped to devices like the graphic card from the 4gig point is remapped higher or not totally lost. If you don't know what I'm talking about, you might want to refer to http://www.codinghorror.com/blog/archives/000811.html and http://support.microsoft.com/kb/929605/en-us .

Specifically, I'm planning on building my next computer with the P5K Deluxe motherboard from Asus and I'm wondering if that motherboard has a memory remapping option.

Thanks

--- Edited ---

As people give me more information of their motherboards, I'll try to keep an updated list of motherboards with memory remapping options.

BIOS option

ASUS P5K Deluxe ( ref: dekruyter - http://www.xtremesystems.org/forums/...01&postcount=2 )
ASUS P5B Line ( ref: dnottis - http://www.xtremesystems.org/forums/...37&postcount=4 )

No problem - Auto detect/remapping ?

Gigabyte DS3 ( ref: dnottis - http://www.xtremesystems.org/forums/...37&postcount=4 )
DFI 680i LT ( ref: virtualrain - http://www.xtremesystems.org/forums/...36&postcount=8 )

[dekruyter]

Yes it does, and it works fine.

[delizseemack]

Yes it does, and it works fine.

Thanks for the info dekruyter,

I'm still wondering if someone has compiled a list of motherboards that supports some kind of memory remapping features.

[dnottis]

The P5B line has a setting to enable memory mapping in the BIOS. My DS3 doesn't, but I have no problems seeing all 4 GB in Vista 64.

[virtualrain]

Hello,

I'm looking for a list of mainstream motherboards that supports some kind of memory remapping features for 64bits OSes so that memory mapped to devices like the graphic card from the 4gig point is remapped higher or not totally lost. If you don't know what I'm talking about, you might want to refer to http://www.codinghorror.com/blog/archives/000811.html and http://support.microsoft.com/kb/929605/en-us .

Specifically, I'm planning on building my next computer with the P5K Deluxe motherboard from Asus and I'm wondering if that motherboard has a memory remapping option.

Thanks

I think you are confused (either that or I am!). The articles you quote that refer to a problem seeing all 4GB of RAM apply to running a 32-bit OS. If you are running a 64-bit OS, there is no issue since there is plenty of memory space to map I/O memory space above physical memory and AFAIK the OS will take care of this independent of what motherboard you are using. Therefore it's not a motherboard option but a capability of 64-bit OS's to handle a full 4GB of RAM.

[dekruyter]

I think you are confused (either that or I am!). The articles you quote that refer to a problem seeing all 4GB of RAM apply to running a 32-bit OS. If you are running a 64-bit OS, there is no issue since there is plenty of memory space to map I/O memory space above physical memory and AFAIK the OS will take care of this independent of what motherboard you are using. Therefore it's not a motherboard option but a capability of 64-bit OS's to handle a full 4GB of RAM.

No, you are wrong. If you run Vista x64 without enabling re-mapping you do not see 4gb with a P6K Deluxe (been there, done it), and I assume, all motherboards. Whether it's buried in the bios (auto), an option in the bios (like the P5K), or not an option at all are the differences (choices).

[delizseemack]

I think you are confused (either that or I am!). The articles you quote that refer to a problem seeing all 4GB of RAM apply to running a 32-bit OS. If you are running a 64-bit OS, there is no issue since there is plenty of memory space to map I/O memory space above physical memory and AFAIK the OS will take care of this independent of what motherboard you are using. Therefore it's not a motherboard option but a capability of 64-bit OS's to handle a full 4GB of RAM.

If read the first link that I provided carefully, you can find:

The proper solution to this whole conundrum is to use a 64-bit operating system. However, even with a 64-bit OS, you'll still be at the mercy of your motherboard's chipset and BIOS; make sure your motherboard supports using 4 GB or more of memory, as outlined in this MSKB article. {...} The memory hole for IO still exists in the 64-bit world, but most modern BIOSes allow you to banish the IO memory hole (pdf) to some (for now) ridiculously high limit when you're running a 64-bit OS.

While reading the pdf in the last quote, you can find:

So we know now that this hole is really just a product of 32-bit address space limitations and software compatibility.
The next thought might be: Doesn’t a 64-bit CPU with 64-bits of address space solve this? Well, unfortunately, the answer is no. Despite that Opteron™ can address up to 1TB of memory and can run in 64-bit mode, it doesn’t solve the problem since the BIOS does not know which Operating System the machine will boot and must map all devices below 4GB for compatibility reasons.
As long as the BIOS must support 32-bit Operating Systems, the missing memory will still be an issue.

I hope it can help you better understand the situation and find out why I'm looking for a list of motherboards that support some kind of memory remapping features.

[virtualrain]

Yeah... OK... I definitely stand corrected. Thanks.

My DFI 680i LT doesn't have a memory mapping option but I'm running Vista x64 with 4GB of RAM and see it all no problems. Installing Vista x64 on a system with 4GB of RAM is a whole other problem... http://support.microsoft.com/kb/929777

[delizseemack]

As a cross reference, here is what I got on an other forum:

http://forums.anandtech.com/messagev...readid=2064835