DMI only reports 64GB of 128GB installed

[Pavel Dolinin]

on a Dual CPU system, in System Detail,s see only half of the memory (64GB)
System Details:
# System Details Report
---

## Report details
- **Date generated:** 2026-01-07 20:45:16

## Hardware Information:
- **Hardware Model:** INTEL X99-2D4
- **Memory:** 64.0 GiB
- **Processor:** Intel® Xeon® E5-2699C v4 × 88
- **Graphics:** NVIDIA GeForce RTX™ 2080 Ti
- **Graphics 1:** NVIDIA GeForce RTX™ 2080 Ti
- **Disk Capacity:** 12.3 TB

## Software Information:
- **Firmware Version:** 5.11
- **OS Name:** Ubuntu 25.10
- **OS Build:** (null)
- **OS Type:** 64-bit
- **GNOME Version:** 49
- **Windowing System:** Wayland
- **Kernel Version:** Linux 6.17.0-8-generic

But it's ok in free:
free -h
               total used free shared buff/cache available
Mem: 121Gi 5.4Gi 112Gi 159Mi 4.3Gi 116Gi
Swap: 232Gi 0B 232Gi

ProblemType: Bug
DistroRelease: Ubuntu 25.10
Package: gnome-control-center 1:49.0-1ubuntu2
ProcVersionSignature: Ubuntu 6.17.0-8.8-generic 6.17.2
Uname: Linux 6.17.0-8-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.33.1-0ubuntu3
Architecture: amd64
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Wed Jan 7 20:41:11 2026
InstallationDate: Installed on 2025-10-28 (71 days ago)
InstallationMedia: Ubuntu 25.04 "Plucky Puffin" - Release amd64 (20250415.3)
ProcEnviron:
 LANG=en_US.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=xterm-256color
 XDG_RUNTIME_DIR=<set>
SourcePackage: gnome-control-center
UpgradeStatus: Upgraded to questing on 2025-10-30 (69 days ago)

[Daniel van Vugt (vanvugt)]

Presumably 'cat /proc/meminfo' shows the correct amount too?

[Daniel van Vugt (vanvugt)]

It appears gnome-control-center looks in two places for memory size:

1. Look in /sys/devices/virtual/dmi/id and get MEMORY_ARRAY_NUM_DEVICES, then sum up all of MEMORY_DEVICE_*_SIZE.

But those might not exist on some hardware (and I wonder could be buggy on some BIOSes?). So if the first calculation amounts to zero it tries this instead:

2. glibtop_get_mem(), which seems to just do the equivalent of: grep MemTotal /proc/meminfo

I'm guessing most likely method #1 is coming up with a bogus answer on your machine? Does it really have two separate CPUs?

[Pavel Dolinin (pavel-dolinin)]

Output:
cat /proc/meminfo
MemTotal: 127410952 kB
MemFree: 55900700 kB
MemAvailable: 114650688 kB
Buffers: 525628 kB
Cached: 58652332 kB
SwapCached: 0 kB
Active: 12667148 kB
Inactive: 54376184 kB
Active(anon): 8908500 kB
Inactive(anon): 0 kB
Active(file): 3758648 kB
Inactive(file): 54376184 kB
Unevictable: 80 kB
Mlocked: 80 kB
SwapTotal: 244196348 kB
SwapFree: 244196348 kB
Zswap: 0 kB
Zswapped: 0 kB
Dirty: 22696 kB
Writeback: 0 kB
AnonPages: 7867992 kB
Mapped: 2554824 kB
Shmem: 1043404 kB
KReclaimable: 1660356 kB
Slab: 2716396 kB
SReclaimable: 1660356 kB
SUnreclaim: 1056040 kB
KernelStack: 59408 kB
PageTables: 115564 kB
SecPageTables: 15496 kB
NFS_Unstable: 0 kB
Bounce: 0 kB
WritebackTmp: 0 kB
CommitLimit: 307901824 kB
Committed_AS: 56926900 kB
VmallocTotal: 34359738367 kB
VmallocUsed: 598240 kB
VmallocChunk: 0 kB
Percpu: 203104 kB
HardwareCorrupted: 0 kB
AnonHugePages: 0 kB
ShmemHugePages: 0 kB
ShmemPmdMapped: 0 kB
FileHugePages: 708608 kB
FilePmdMapped: 0 kB
CmaTotal: 0 kB
CmaFree: 0 kB
Unaccepted: 0 kB
Balloon: 0 kB
HugePages_Total: 0
HugePages_Free: 0
HugePages_Rsvd: 0
HugePages_Surp: 0
Hugepagesize: 2048 kB
Hugetlb: 0 kB
DirectMap4k: 4831772 kB
DirectMap2M: 35958784 kB
DirectMap1G: 95420416 kB

[Daniel van Vugt (vanvugt)]

What files do you find in /sys/devices/virtual/dmi/id ?

And what output do you get from this command?;

  sudo dmidecode -t17

[Daniel van Vugt (vanvugt)]

Or this command, which shows the actual data gnome-control-center is using:

  sudo udevadm info -t | grep MEMORY

[Pavel Dolinin (pavel-dolinin)]

ls -la /sys/devices/virtual/dmi/id/
total 0
drwxr-xr-x 3 root root 0 Jan 8 07:03 .
drwxr-xr-x 3 root root 0 Jan 8 07:03 ..
-r--r--r-- 1 root root 4096 Jan 8 16:28 bios_date
-r--r--r-- 1 root root 4096 Jan 8 16:28 bios_release
-r--r--r-- 1 root root 4096 Jan 8 07:03 bios_vendor
-r--r--r-- 1 root root 4096 Jan 8 16:28 bios_version
-r--r--r-- 1 root root 4096 Jan 8 16:28 board_asset_tag
-r--r--r-- 1 root root 4096 Jan 8 07:04 board_name
-r-------- 1 root root 4096 Jan 8 16:28 board_serial
-r--r--r-- 1 root root 4096 Jan 8 07:03 board_vendor
-r--r--r-- 1 root root 4096 Jan 8 16:28 board_version
-r--r--r-- 1 root root 4096 Jan 8 16:28 chassis_asset_tag
-r-------- 1 root root 4096 Jan 8 16:28 chassis_serial
-r--r--r-- 1 root root 4096 Jan 8 07:04 chassis_type
-r--r--r-- 1 root root 4096 Jan 8 16:28 chassis_vendor
-r--r--r-- 1 root root 4096 Jan 8 16:28 chassis_version
-r--r--r-- 1 root root 4096 Jan 8 07:04 modalias
drwxr-xr-x 2 root root 0 Jan 8 16:28 power
-r--r--r-- 1 root root 4096 Jan 8 16:28 product_family
-r--r--r-- 1 root root 4096 Jan 8 07:03 product_name
-r-------- 1 root root 4096 Jan 8 16:28 product_serial
-r--r--r-- 1 root root 4096 Jan 8 16:28 product_sku
-r-------- 1 root root 4096 Jan 8 07:04 product_uuid
-r--r--r-- 1 root root 4096 Jan 8 07:03 product_version
lrwxrwxrwx 1 root root 0 Jan 8 07:03 subsystem -> ../../../../class/dmi
-r--r--r-- 1 root root 4096 Jan 8 07:03 sys_vendor
-rw-r--r-- 1 root root 4096 Jan 8 07:03 uevent
and
sudo dmidecode -t17
[sudo: authenticate] Password:
# dmidecode 3.6
Getting SMBIOS data from sysfs.
SMBIOS 3.0.0 present.

Handle 0x0057, DMI type 17, 40 bytes
Memory Device
 Array Handle: 0x0056
 Error Information Handle: Not Provided
 Total Width: Unknown
 Data Width: Unknown
 Size: No Module Installed
 Form Factor: Unknown
 Set: None
 Locator: NO DIMM
 Bank Locator: NO DIMM
 Type: Unknown
 Type Detail: Unknown

Handle 0x0058, DMI type 17, 40 bytes
Memory Device
 Array Handle: 0x0056
 Error Information Handle: Not Provided
 Total Width: Unknown
 Data Width: Unknown
 Size: No Module Installed
 Form Factor: Unknown
 Set: None
 Locator: NO DIMM
 Bank Locator: NO DIMM
 Type: Unknown
 Type Detail: Unknown

Handle 0x005B, DMI type 17, 40 bytes
Memory Device
 Array Handle: 0x0059
 Error Information Handle: Not Provided
 Total Width: 72 bits
 Data Width: 72 bits
 Size: 32 GB
 Form Factor: DIMM
 Set: None
 Locator: DIMM_C1
 Bank Locator: NODE 2
 Type: DDR4
 Type Detail: Synchronous
 Speed: 2400 MT/s
 Manufacturer: Hynix Semiconductor
 Serial Number: 11B355DE
 Asset Tag: DIMM_C1_AssetTag
 Part Number: HMA84GR7AFR4N-UH
 Rank: 2
 Configured Memory Speed: 2400 MT/s
 Minimum Voltage: 1.14 V
 Maximum Voltage: 1.26 V
 Configured Voltage: 1.2 V

Handle 0x005D, DMI type 17, 40 bytes
Memory Device
 Array Handle: 0x0059
 Error Information Handle: Not Provided
 Total Width: Unknown
 Data Width: Unknown
 Size: No Module Installed
 Form Factor: Unknown
 Set: None
 Locator: NO DIMM
 Bank Locator: NO DIMM
 Type: Unknown
 Type Detail: Unknown

Handle 0x005F, DMI type 17, 40 bytes
Memory Device
 Array Handle: 0x005E
 Error Information Handle: Not Provided
 Total Width: Unknown
 Data Width...

[Daniel van Vugt (vanvugt)]

It appears your SMBIOS (or the kernel) is only reporting two 32GB DIMMs, hence 64GB. So it seems to be either a BIOS or a kernel problem.

[Pavel Dolinin (pavel-dolinin)]

top, htop, and free all show the correct amount of available memory.

[Daniel van Vugt (vanvugt)]

Yes, most tools will be using /proc/meminfo which shows a more correct value. It's not strictly wrong for gnome-control-center to probe the BIOS instead because that will give you a total without rounding errors (which would incur more bug reports from people).

It's only the BIOS, or the way the kernel is reading the BIOS, that seems to be at fault here.

[Ian Whitfield (ijwhitfield)]

Hi, thanks for opening a bug report!

Could you try installing a mainline kernel? Our latest mainline build is available here: https://kernel.ubuntu.com/mainline/v6.19-rc5/
Instructions for installing mainline kernels are available here: https://wiki.ubuntu.com/Kernel/MainlineBuilds

If the problem is resolved on mainline, we'll need to look into what patches to backport or where Ubuntu has created a regression from upstream.