# ASUS A8N32-SLI mobo + 4GB. Help.



## ClickCardo (Jul 8, 2005)

I've search other threads, but cannot solve or completely understand my particular situation.


Have a ASUS A8N32-SLI mobo with 2x1GB sticks of Crucial DDR-400 memory running XP Pro SP2 perfect. I have version 1009 of the AMI BIOS. Added 2 more 1GB of the same Crucial id memory, although they do not look physically identical, and booted up. I did not make any BIOS or boot.ini changes.

Belarc Advisor shows 2,288MB of memory with all 4x1GB DIMM's showing.

MS System Info tool shows 4,096MB Physical memory and 1.536GB available.

CPU-Z shows 4,096MB at 200MHz Frequency. For it's SPD all 4 sticks have same timings and max Bandwidth.
However on the two new sticks the mfgr.# is all zero's, the part # is blank and the serial # is all F's.
Everything reads fine for the 2 old sticks.

I understand that XP cannot use ALL the 4GB, but it does not seem to be using ANY of the 2 new GB's. Can someone help me use them.


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## carsey (Aug 19, 2006)

If the new sticks are of a slower speed than the original ones then it is likely to cause a error. it may include that the new only operates at the speed of the old RAM or that it doesnt register on the system.

have you tried the 2 new sticks on their own to see if they are not faulty??


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## ClickCardo (Jul 8, 2005)

carsey

I think it may be something else since CPU-Z shows them all at the same Frequency (speed?). Also, I went into the BIOS and it shows 4GB installed and 3040MB "usable" whatever usable means. I also did a memtest-86 pass. It showed 3039MB of memory and passed all tests without errors once.


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## dai (Jul 2, 2004)

xp will not acknowledge it all 3g is the norm you will see it all with vista


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## ClickCardo (Jul 8, 2005)

My question still is not answered. I'm only seeing TWO (2GB) not 3GB more or less 4GB.





dai said:


> xp will not acknowledge it all 3g is the norm you will see it all with vista


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## dai (Jul 2, 2004)

xp recognises 2g,vista will recognise about 8 terbytes from what i can remember
some m/b only recognise 3g


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## UncleMacro (Jan 26, 2005)

Take a look in the Device Manager and check out how the memory is actually being used. To get the screen below Click the "View" menu, then "Resources by type", then click the "+" to the left of "Memory". If your RAM is being used by some I/O devices then this screen will show what they are and how much RAM address space they're using up. Video cards are usually the biggest memory hogs but they shouldn't use near as much RAM as you're losing. If you post a screenshot then we can take a look.


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## ClickCardo (Jul 8, 2005)

I put a /3GB switch in boot.ini and now see 3040MB memory. I did what you suggested but cannot read hex too well. With this new info would it still be worth posting that info? And why is only 3GB usable in the BIOS before I even get into XP?

Thanks


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## UncleMacro (Jan 26, 2005)

> I did what you suggested but cannot read hex too well. With this new info would it still be worth posting that info?


I'm a programmer so I read hex just fine. If you'd like to answer the mystery of where your RAM is going then go ahead and post it. Usually it's the video card but post it if you'd like to know for sure.



> And why is only 3GB usable in the BIOS before I even get into XP?


The motherboard has to allocate address space (ranges of RAM addresses) in order to access various devices like disk controllers, sound controllers, USB, FireWire, etc. Video cards take up the most space because their video RAM has to be mapped into your 4 gig of address space. Running a 64 bit operating system with a motherboard which supports it properly allows you to get your whole 4 gig of useable RAM. But a 32 bit operating system has to make room for the previously mentioned devices so it wastes some of your RAM in the process.


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## ClickCardo (Jul 8, 2005)

UncleMacro

I've attached a jpg screen copy of what you requested. Thanks for taking the time to look at it. I'm still puzzed why if you only have 4GB and the motherboard has to allocate memory before you even load a OS that a 64-bit OS allows you to use the whole 4gb when it is the same devices and memory used for them as 32-bit os?

Thanks
CC


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## UncleMacro (Jan 26, 2005)

According to that memory map you have 256 MB going to "Motherboard resources". I'm not sure what that is, really. Let's just hope they're not wasting that much of it. You also have 256 MB going to your 7600 GT. That's only the space for one output assuming you have 256 MB of video RAM. The "PCI standard PCI-to-PCI bridge" takes up 512 MB and overlaps with the 7600 GT so I would guess that it includes both outputs for your 7600 GT even if you're just using one of them. That means a total of 512 MB is going to your 7600 GT (assuming that's what the "PCI standard PCI-to-PCI bridge" thing is). The rest is going to various devices. I looked at the BIOS updates for the A8N32-SLI and none of them mentioned rearranging the way they allocate devices. But sometimes they don't mention all their fixes. Flashing the motherboard BIOS could affect how they are allocated. You might check to see if you have the latest BIOS just in case.



> I'm still puzzed why if you only have 4GB and the motherboard has to allocate memory before you even load a OS that a 64-bit OS allows you to use the whole 4gb when it is the same devices and memory used for them as 32-bit os?


When you're running a 32 bit OS there is only 4 GB of addresses available. If it allocates 1 GB to various devices then it only has 3 GB of addresses available to access your RAM. So even if you have 4 GB of RAM installed, it can only access 3 GB of it. The limitation is that you only have 4 GB of address space available and it has to be shared. If you run a 64 bit OS (which requires a 64 bit CPU and a motherboard which properly supports it) then you have 16 exabytes (that's a lot) of address space. That's about 16 billion GB of address space. 64 bit addresses can easily hold your 4 GB of RAM and 1 GB of space for your various devices at the same time. So if your motherboard provides full 64 bit support then you can get access to your full 4 GB of RAM when running a 64 bit OS. I haven't done this myself but I checked the ASUS A8N32-SLI manual and I think that you have to set the "Hardware memory hole" option to "Enabled" to get the full 4 GB with a 64 bit OS. You might also have to fiddle with the "MTRR mapping" option.


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## ClickCardo (Jul 8, 2005)

UncleMacro

Thanks for interpreting the memory mapping for me. It makes some more sense now.

About the second point though I still do not understand. If there is only 4GB total in the machine and the resources are taking 1GB, which is close to what your explanation states, then only 3GB is left. This would be the case for both 64-bit and 32-bit since they are the same devices taking the same amount of memory out for both. I understand if I had MORE THAN 4GB where the 64-bit OS would allow more but still do not understand the explanation when there is 4GB or less?


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## UncleMacro (Jan 26, 2005)

> This would be the case for both 64-bit and 32-bit since they are the same devices taking the same amount of memory out for both.


A motherboard which properly supports 64 bit CPUs and OSes is not limited to a 32 bit address space. I believe the way it works (I've never done this) is that the various devices are still allocated to addresses less than 4GB but RAM can be allocated both below the 4GB boundary and above it. So when running in 64 bit mode it allocates RAM to the first 3 GB. Then it allocates your devices in the next 1GB. Then it allocates the rest of your RAM starting at 4GB and up to 5 GB (assuming you have 4 GB of RAM). RAM addresses are not limited to 32 bit values on that kind of motherboard. But I think you have to set that BIOS option to tell the motherboard to allocate the RAM that way (that's the "memory hole" they're talking about).


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## ClickCardo (Jul 8, 2005)

I've been having problems with Firefox 1.5.0.7 locking up lately. It's even hard to term the process from task manager if I even can at that point. I'll try without /3GB awhile then with it again and see if I can discern any pattern. I might try looking at IE7 too which I just installed.


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