Asus 4 GB

[jobe_17]

Good day,

Odd problem with an Asus p4p800SE ( latest bios ) and 4 1GB sticks of kingston memory

if I run an ATI 9800 128 MB then the memory shows as 3.5 GB

if I run a 9600XT 256 MB then it shows as 3 GB

If I take the last 1 GB Stick out then it reports 3 GB correctly.

Any ideas why the memory is dropping or why its not reporting 4 GB??

 

[DiscoDuck]

I wouldnt worry too much about 3 versus 4 gb of ram, especially if its not a 64 bit OS.....especially in and older machine. Its not worth worrying why, use the card and ram combo you like best and start saving money for a new rig

 

[jobe_17]

Indeed agree,

The situation is that someone wants to purchase this system

I had it setup with 1 GB and a 9000 128 MB.

He ask me to install his hardware ( 4 1 GB sticks and a 9800 all in wonder )

I was hoping to find somekind of explaination for him when he asks why he can't run 4 Gb as even with all 4 GB installed the system crashes speratically

 

[jitpublisher]

Extremely common problem, and probably the most asked question ever to hit the forums, well maybe right behind "new system no display"

Okay...in a nutshell here is the scoop.

What is not reporting 4 gig?
Your BIOS, or your OS, or both?
If this is in the OS, If you are running a 32 bit OS, the above scenerio is perfectly normal.
If you do not get the full 4 gig memory count during POST, you must enable memory remapping, or the memory hole feature as some older BIOS's call it to for the BIOS to remap memory above the 3 gig address layer.
But, when you do get the full 4 gig counting up during the POST memory test, your OS is only going to display around 3~3.5 gig available for use, depending exactly on how much other memory is in your system. A 32 bit OS will address 4 gig of memory and no more**, but this includes ALL the memory in your system. What is over after assigning all of the other memory in your system address space (the video card, the controllers, the system cache, the CPU cache, the harddrive cache, etc up to what makes a total of 4 gig is assigned to your RAM. Now, Windows only displays how much RAM is being assigned, it does not take into account all the other items is has already allocated memory space for.
To address above 4 gig of memory total, you need a 64 bit OS, and you still then for sure must make certain the memory remapping feature is enabled, or even the 64 bit OS will not have access to anything above 3 gig.

As for the crashing problem, running 4 sticks of memory can be troublesome due to the fact it simply is taking more system overhead to run 4 sticks. It is normal to have to increase the RAM voltage slightly to get 4 sticks running stable, or raise the timings. Best scenerio for 4 gig is 2x2 gig.

**This does not apply to earlier 32 bit versions of Windows Server. It addresses memory in a completely different way, and will address more than 4 gig, but we are not concerned about this in this situation.

 

[jobe_17]

thank you jitpublisher for such an informative answer.

Issue is indeed the bios not reporting total memory and after reading that I indeed had to smack myself on the forehead V8 Style

I think I am gonna just remove the 4th stick and run it like that

thank you again.

 

[jitpublisher]

You are very welcome.
It is best though to keep all 4 sticks in, that way you are running in dual channel mode. Simply go into the BIOS and look for the memory remapping feature, and turn it on. Some BIOS will have 2 settings, Hardware and Software remapping.
You will want to turn on Software remapping, leave the hardware remapping turned off, if your system has these options.
That way you are running dual channel, and Windows has access to every tiny bit of memory that it can possibly make use of.

 

[mikrev007]

jitpublisher, I think you have misunderstood what memory remapping does. It takes some of the RAM below 4G and moves it up above it. If you are running 32bit Windows you can actually lose even more RAM by enabling it, because often it remaps on a 1G-boundary (like, 2.75 could end up as 2.00 in Windows, or 3.50 ends up as 3.00).

My point is, no matter what, you won't get any more RAM out of it in 32bit Windows.

 

[jitpublisher]

jitpublisher, I think you have misunderstood what memory remapping does. It takes some of the RAM below 4G and moves it up above it. If you are running 32bit Windows you can actually lose even more RAM by enabling it, because often it remaps on a 1G-boundary (like, 2.75 could end up as 2.00 in Windows, or 3.50 ends up as 3.00).

My point is, no matter what, you won't get any more RAM out of it in 32bit Windows.

Nope, I know exactly what it does. Your are thinking of Hardware remapping, which is compeltely different.
Software remapping must be enabled.....if your BIOS supports the feature, in order for the OS to have access to memory over 3 gig.
Even if you only have a 32 bit OS, you could end up with only 2 gig, or even less memory available for the OS to use if you had say a 1 gig video card, and the motherboard does not by default have this feature enabled (most newer boards simply do this by default, many older boards do require you to enable it as an option)

 

[mikrev007]

No, hardware and software remapping does the exact same thing. The difference is how it is done... it remaps ram up above 4G - a place where 32bit xp/vista cannot go.

 

[mikrev007]

And don't be fooled by the word "software" - they are both done in hardware (and only AMD boards have two options. Intels boards just have "remapping")