Missing RAM?

[ammofreak]

Hi :

Been trying to figure out a RAM memory puzzle. I am running Ubuntu 12.04 (64bit) with a dedicated graphics card (Nvidia) & 4GB of RAM. However, when I look at system info, only 2.9 GB of RAM is showing. This amount is verified when I run System Monitor, free, or htop. The 4 RAM sticks are seated properly as I checked my BIOS which shows the actual 4GB RAM.

My question: where is the missing 1GB of RAM?

[dabl]

Does all 4 GB show in BIOS? What does lshw show?

[ammofreak]

Hi dabl :
Thanks for the reply!

As to your inquiries: 1) Yes, 4GB of RAM showing in BIOS
2) lshw shows banks 0-3 of DDR RAM

[oldfred]

Then are you sure you are running 64 bit?

32 or 64 bit

uname -a

i386 or i686 = 32-bit
x86_64 = 64-bit

lscpu

[ammofreak]

Hi oldfred :
Thanks for the reply!

uname -a shows Linux (my host name) 3.5.0-21-generic..x86_64 GNU/Linux

[dannyboy79]

what does this return?

cat /proc/meminfo

[tlhIngan]

What's your motherboard, man?

[ammofreak]

Hi everyone :
Thanks again for replies!

Just to go over some of the pertinent info I garnered so far:

1) the BIOS is registering all 4 GB of RAM. I therefore have to assume the sticks are OK.
2) I really do not know what the m/b is other than the computer is a Dimension 8400 with a Pentium 4 CPU (3.2GHz) H/T capable for dual core.
3) Even though I am running a 64 bit OS, the m/o is only capable of 4GB with 1 GB DDR2 maximum size sticks & 4 memory slots 0-3
4) Interesting fact: ran memtest (on grub menu) at bootup & RAM is only showing 3GB! Note: this test would void any Nvidia addressing problems as posted, right?


Here is the memory info from sudo lshw:

*-memory
          description: System Memory
          physical id: 1000
          slot: System board or motherboard
          size: 4GiB
        *-bank:0
             description: DIMM DDR Synchronous 533 MHz (1.9 ns)
             product: 1G-UDIMM
             vendor: Kingston
             physical id: 0
             serial: 2C0D2203
             slot: CHANNEL A DIMM 0
             size: 1GiB
             width: 64 bits
             clock: 533MHz (1.9ns)
        *-bank:1
             description: DIMM DDR Synchronous 533 MHz (1.9 ns)
             product: 1G-UDIMM
             vendor: Kingston
             physical id: 1
             serial: 2C0D2303
             slot: CHANNEL B DIMM 0
             size: 1GiB
             width: 64 bits
             clock: 533MHz (1.9ns)
        *-bank:2
             description: DIMM DDR Synchronous 533 MHz (1.9 ns)
             product: 1G-UDIMM
             vendor: Kingston
             physical id: 2
             serial: 2C0DF402
             slot: CHANNEL A DIMM 1
             size: 1GiB
             width: 64 bits
             clock: 533MHz (1.9ns)
        *-bank:3
             description: DIMM DDR Synchronous 533 MHz (1.9 ns)
             product: 1G-UDIMM
             vendor: Kingston
             physical id: 3
             serial: 2C0DE837
             slot: CHANNEL B DIMM 1
             size: 1GiB
             width: 64 bits
             clock: 533MHz (1.9ns)

It is quite apparent that all 4 RAM sticks are good & memory is being registered at 4GB.

[dabl]

This situation appears to be a limitation of the Dell Dimension 8400 motherboard design:

http://support.dell.com/support/edoc....htm#wp1052394

Specifically "Your computer supports a maximum of 4 GB of memory when you use four 1-GB DIMMs. Current operating systems, such as Microsoft® Windows® XP, can only use a maximum of 4 GB of address space; however, the amount of memory available to the operating system is less than 4 GB. Certain components within the computer require address space in the 4-GB range. Any address space reserved for these components cannot be used by computer memory."

(This was obviously written ~10 years ago ...).

However, 3GB is plenty of memory for most typical usage scenarios with a Linux system. If your productivity requirements often need more than that, then you also seriously need a beefier CPU than the P4.

[ammofreak]

Hi dabl :

Thank you for your time & reply!

As you stated the upper RAM limit on the Dim8400 is 4GB. What gets me is this:

I have been using Ubuntu since 9.04 & my RAM memory alway showed 4GB or there abouts. Now with 12.04, I only get 2.9GB.

And yes, you are right: this is an old computer!. However, it still works beautifully even when I am running Eclipse or Aptana Studio along with 2 or 3 other programs; and a desktop littered with eye candy.

As an aside to a previous post: I removed the Nvidia drivers completely & reverted back to X.Org Nouveau driver but to no avail! Same RAM amount.

Anyway I am declaring this post DEAD! Thank you again dabl & everyone else for the replies and personal time spent on my post.