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Distribution: Slackware64-current with "True Multilib" and KDE4Town.
Posts: 9,097
Rep:
Slackware64 Only See 3.25 out of 4 Gigs of RAM.
A neighbor (and Slackware convert ) is running a "old" Dell Dimension 9100 with an Intel P4, 64-bit processor with Hyperthreading, EM64T, etc. I'm always amazed how well it runs just about everything he has thrown at it.
The maximum amount of RAM for the motherboard is 4 Gigs, which he just installed yesterday.
He asked me to take a look as Slackware64 is only showing 3.25 Gigs of RAM.
The BIOS shows the entire 4 Gigs and reports all of it is available to the operating system.
However, GKrellm and other various utilities show only 3.25 Gigs
and the system surely isn't using the other 3/4 of a Gig.
Any ideas as to why the RAM isn't being properly used?
Thanks!
Last edited by cwizardone; 07-12-2014 at 08:59 AM.
To be able to use the whole 4GB of RAM the motherboard/BIOS has to support memory remapping, so that it can blend the RAM that is in the PCI memory range to addresses above the 4GB range to make it accessible to the OS.
Look in the BIOS for that machine for an option named "Memery Remapping" or similar and activate it. If it is not present that means that you will not get the 4GB, unless a newer BIOS supports it.
If it's a higher end video chipset like an ATI/AMD or Nvidia it could have a standard 256MB of RAM with a dynamically allocated 512MB Expansion Texture Buffer space in the BIOS also. If not, it could also be a bad memory stick.
You might want to run memtest86 against it to be certain.
Distribution: Slackware64-current with "True Multilib" and KDE4Town.
Posts: 9,097
Original Poster
Rep:
Thanks to everyone for their replies.
Yes, as mentioned in the first post, the board is limited to 4 Gigs.
Yes, the motherboard has been flashed with the latest BIOS, but there is no memory remapping option.
No, it does not have a on-board video card.
Yes, the memory has been tested with Memtext86+ and it passed, no errors.
Memtest86+ showed the memory as,
Quote:
memory: 3326 2758MB/s
Chipset: Intel i945P/G
On the screen during the test there were several spaces, i.e., a long blank space, between 3326 and 2758. I'm not sure what the second number means.
As I said before, the BIOS shows 4 Gigs installed.
I've search the Dell site and haven't, yet, found anything about a limitation on useable RAM.
Last edited by cwizardone; 07-14-2014 at 11:27 PM.
According to this page, the intel 945P/G chipsets support up to 4GB of RAM, but does not support remapping of PCIE/APIC memory, therefore the useable memory is limited to about 3.5 GB.
Code:
Chipset Code Name Part numbers South Bridge Release Date Supported Processors FSB (MHz) Memory Types Max. Memory
945P Lakeport 82945P (MCH) ICH7/ICH7R May 2005 Pentium 4, .... 533/800/1066 DDR2 400/533/667 4 GB[*]
945G Lakeport-G 82945G (GMCH) ICH7/ICH7R May 2005 Pentium 4, .... 533/800/1066 DDR2 400/533/667 4 GB[*]
[*] Remapping of PCIE/APIC memory ranges not supported,[26] some physical memory might not be accessible (e.g. limited to 3.5 GB or similar).
-- SeB
Last edited by phenixia2003; 07-15-2014 at 02:49 AM.
Distribution: Slackware64-current with "True Multilib" and KDE4Town.
Posts: 9,097
Original Poster
Rep:
Quote:
Originally Posted by Labinnah
Are you sure this is 64bit Slackware? It looks like 32bit without "High Memory Support" compilled into kernel.
Yes.
Quote:
Originally Posted by phenixia2003
Hello,
According to this page, the intel 945P/G chipsets support up to 4GB of RAM, but does not support remapping of PCIE/APIC memory, therefore the useable memory is limited to about 3.5 GB.
Code:
Chipset Code Name Part numbers South Bridge Release Date Supported Processors FSB (MHz) Memory Types Max. Memory
945P Lakeport 82945P (MCH) ICH7/ICH7R May 2005 Pentium 4, .... 533/800/1066 DDR2 400/533/667 4 GB[*]
945G Lakeport-G 82945G (GMCH) ICH7/ICH7R May 2005 Pentium 4, .... 533/800/1066 DDR2 400/533/667 4 GB[*]
[*] Remapping of PCIE/APIC memory ranges not supported,[26] some physical memory might not be accessible (e.g. limited to 3.5 GB or similar).
-- SeB
Thanks. That answers the question. Greatly appreciated!
Quote:
Originally Posted by TobiSGD
The second number is the maximum speed of your RAM in MB/s.
Thanks.
Last edited by cwizardone; 07-15-2014 at 12:12 PM.
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) is running a "old" Dell Dimension 9100 with an Intel P4, 64-bit processor with Hyperthreading, EM64T, etc. I'm always amazed how well it runs just about everything he has thrown at it. 
