4GB != 3.25GB

V

vischo

Gawd
Joined
Jul 27, 2005
Messages
854
Just popped in (2) two more 1GB sticks into my machine with (2) two 1GB sticks.... Windows Vista and XP both showing that only 3.25GB are installed.... Tested all configurations 2 sticks vice versa, only 3 sticks, etc... Every other variation shows exactly what it should... Only when all (4) four sticks are in at the same time does Windows only show 3.25GB.... Searched BIOS up and down, no luck.... Any ideas... Specs, should be up to date, in signature line....

Thanks...
 
You are running 32 bit windows. That memory space is reservered by the video card(s) and pci addressing. You need 64bit windows or switch to server which can run those above the 4 gig limit through various ways.
 
wow , you learn something everyday , thats it i am done for today and going to sleep.
 
(cf)Eclipse said:
i try to learn two things every day :D :D
Click to expand...
thats the attitude which made me fall behind in life, shit happens I guess
:D
 
Alright, boys and girls.... Lets dig this one up again. DL'd and installed Vista RC2 64-bit version..... System shows 3.75GB of RAM, show again I say

4GB != 3.75GB

Any suggestions this time around....
 
Have you tried each stick individually?

I mean perhaps one stick is good and the other has been damaged in some way.
 
vischo said:
Alright, boys and girls.... Lets dig this one up again. DL'd and installed Vista RC2 64-bit version..... System shows 3.75GB of RAM, show again I say

4GB != 3.75GB

Any suggestions this time around....
Click to expand...

The rest is reserved for reservations.
:confused:


WTF does that mean anyway. "LOL"
 
So when a 939 is running 4 sticks of memory that are not single sided, its running in single channel mode instead of dual channel mode from what I understand. Is am2 the same way?
 
I'm using 4G of ram in my 939. Do you use the /3GB param in your boot.ini?
 
Jester1550 said:
Have you tried each stick individually?

I mean perhaps one stick is good and the other has been damaged in some way.
Click to expand...

Yes, see first post.

The-One said:
The rest is reserved for reservations.
:confused:

WTF does that mean anyway. "LOL"
Click to expand...

What?

heelix said:
I'm using 4G of ram in my 939. Do you use the /3GB param in your boot.ini?
Click to expand...

You know I don't speak spanish...? What is the /3GB param and why would I need to use it on 64-bit Windows if 64-bit Windows handles like 16GB or more?
 
Hmmn. WinXP-64 and Win2003 show all 4G on the control pannel. XP-32 w/SP2 will more or less limit you to 3G. Bet it is a BIOS setting that is causing you problems.

Few links for ya on the switches. My stuff will leverage the /3G switch. Best to make yoru boot.ini multi-select, just in case your drivers don't like it. Mine did, but were all nvidia (video and mainboard)

(from microsoft)
http://www.microsoft.com/whdc/system/platform/server/PAE/PAEmem.mspx

Also need to enable the MMIO, memory hole, or whatever they named it in your BIOS. Be prepared to reset BIOS if things get ugly. Much better now then when I first got the board.
(me, when I first updated my RAM)
http://forums.techpowerup.com/archive/index.php/t-3572.html

Don't know about Vista. I'll be avoiding that one if at all possible.
 
One other thing - what CPU are you using. Pre-Rev E 939 chips had issues. A Venice core or better was part of the fix.
 
lol.

It is a 32bit addressing problem. But if you are seeing 3.75 or 3.25 or anywhere in between I have the 'fix' for you.

Adjust your AGP page size if you have it, that will make the number move around. I have a Sun W2100Z with 4gb ram, dual opteron 252s, and win64, has this problem almost two years ago.

If you don't have AGP, then I think the hole sits around 3.25Gb b/c of the way PCIe allocates itself for its addressing. Some bioses can mask the pci addresses somewhere else but I'm pretty sure that would only work on a 64bit OS. In win32 you 'might' be able to get it to show 4GB, but I bet acorns to walnuts it can't use those up sections of ram.
 
vischo said:
Alright, boys and girls.... Lets dig this one up again. DL'd and installed Vista RC2 64-bit version..... System shows 3.75GB of RAM, show again I say

4GB != 3.75GB

Any suggestions this time around....
Click to expand...

Guys... read this post.... I understand the 32Bit issue and am now talking about WIN VISTA 64Bit....
 
I discuss Win64 in the sticky. The same issues still apply: you have to have a motherboard that can map over the 4 gig line, you need to have that feature enabled in the BIOS, and you have to have drivers that work correctly with large addresses, and so on.

What people often call "Enthusiast" motherboards often don't have the drivers and sometimes don't have the hardware. What people generalize as "server" motherboards usually do have the hardware and driver support.
 
i have a similar issue and its becasue of my Mobo. research your mobo and see what it will report.

quote from MSI about my mobo.

"Due to the South Bridge resource deployment, the system density will only be detected up to 3+ GB (not full 4GB) when each DIMM is installed with an 1GB memory module "
 
Which specific southbridge chip does your motherboard use, delemorte?
 
I have a gigabyte s939 nforce3 mobo and I have a setting in Expert Chipset Config menu that says 4GB mem remap enable/disable

And my board was not an "enthusiast board"

The point of this post is that some mainstream mobos have it too...
 
Is there anything about a memory hole in the BIOS? I had to just that in order to get it to see all 4gb. It was a while ago though and I am not home atm, otherwise I would dig into it a bit for you.
 
fuelvolts said:
The point of this post is that some mainstream mobos have it too...
Click to expand...
That point was included in my previous post. Thanks for reenforcing it!
 
You must log in or register to reply here.
Back
Top