my own more than 3GB memory problem

mimis2008 · 11-25-2008, 12:49 PM

Hello everybody

I have the problem of "seeing" the 4GB (2x2GB DIMMs) on my laptop (a DELL Precision M90) running SuSE 11.0.

Here is a descritpion of the laptop:

Code:

bwv988:/usr/src/linux # uname -a
Linux bwv988 2.6.25.18-0.2-default #1 SMP 2008-10-21 16:30:26 +0200 x86_64 x86_64 x86_64 GNU/Linux
bwv988:/usr/src/linux # free -m
             total       used       free     shared    buffers     cached
Mem:          3021       3002         18          0        275       1783
-/+ buffers/cache:        944       2077
Swap:         8001          0       8001

Note that my two DIMMs appear on dmidecode (output not included here).

Now begins what I find curious: I also have a DELL server T300 with 12GB physical memory: although the two systems are (to my best knowledge) identical, the T300 "sees" the 12GB without problem:

Code:

rafale:/usr/src/linux # uname -a
Linux rafale 2.6.25.18-0.2-default #1 SMP 2008-10-21 16:30:26 +0200 x86_64 x86_64 x86_64 GNU/Linux
rafale:/usr/src/linux # free -m
             total       used       free     shared    buffers     cached
Mem:         12040       2872       9167          0        544       1264
-/+ buffers/cache:       1063      10977
Swap:        16574          0      16574

Also note that the two kernels produce exactly the same configuration record (using the

Code:

make xconfig

tool in /usr/src/linux).

What might be at play here?

Thanking in advance

mimis

arizonagroovejet · 11-25-2008, 01:20 PM

What chipset is in your laptop?

I did some experiments with 4GB of ram recently in two different machines at work. One machine has the Intel 965 chipset and Linux sees all 4GB. The other machine which is older has some older Intel chipset, 945 I think, (the machine is at work and I'm not) and I couldn't get it to see all 4GB. Both machines had identical installations on them (we use AutoYaST).

See also http://www.linuxquestions.org/questi...memory-578912/

aenright · 11-25-2008, 01:31 PM

Hello mimis2008,

I doubt that your laptop and server are anywhere near the same hardware, so compairing the two most likely will not help you. The first thing that comes to mind is the fact that most laptops will "share" system RAM with the video card. If the laptop has an integrated nVidia or ATI video controller it may be grabbing the RAM. Intel based, onboard video does the same thing, but I don't recal ever seing one that will actually grab up to 1GB of RAM. I would check that in the BIOS. While you are in the BIOS, look to see if there are any other settings that are memory related that you might be able to tweek. Do you have any other frame of reference on the laptop (ie have you installed another OS on it and checked to see if it recognized all the RAM in the past?)

Hope this helps,
~Art

mimis2008 · 11-26-2008, 04:33 AM

Thank you arizonagroovejet !
Thank you Arthur !

This is my lspci output [some of it]

Code:

bwv988:~ # lspci
00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:01.0 PCI bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express PCI Express Root Port (rev 03)

Taking a look on the link below
http://www.linuxquestions.org/questi...memory-578912/
I think I must consider my self one more of the unfortunate cases with an old chipset!

once again thank you both for your time

mimis