XPS 3970 Only 8GB RAM in use out of 16GB

I have an XPS with soldered RAM, I don’t know for how long but Manjaro seems to be only using 8GB. I became suspicious after noticing some blurry text/scrolling issues in Chrome.

Output of two inxi commands, one for my general system and the other for my memory.
memtest seems to have only noticed 8GB also.

inxi -Fazy output:

System:
  Kernel: 4.19.207-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0 
  parameters: BOOT_IMAGE=/boot/vmlinuz-4.19-x86_64 
  root=UUID=8da11d46-7428-4ae1-a49b-34e15d5508b0 rw quiet 
  Console: tty pts/1 wm: kwin_x11 DM: SDDM Distro: Manjaro Linux 
  base: Arch Linux 
Machine:
  Type: Laptop System: Dell product: XPS 13 9370 v: N/A serial: <filter> 
  Chassis: type: 9 serial: <filter> 
  Mobo: Dell model: 0F6P3V v: A00 serial: <filter> UEFI-[Legacy]: Dell 
  v: 1.0.2 date: 12/06/2017 
Battery:
  ID-1: BAT0 charge: 27.0 Wh (61.4%) condition: 44.0/52.0 Wh (84.5%) 
  volts: 7.6 min: 7.6 model: SMP DELL G8VCF6C type: Li-poly serial: <filter> 
  status: Discharging 
CPU:
  Info: Quad Core model: Intel Core i7-8550U socket: BGA1356 (U3E1) 
  note: check bits: 64 type: MT MCP arch: Kaby Lake note: check family: 6 
  model-id: 8E (142) stepping: A (10) microcode: EA cache: L1: 256 KiB 
  L2: 8 MiB L3: 8 MiB 
  flags: avx avx2 lm nx pae sse sse2 sse3 sse4_1 sse4_2 ssse3 vmx 
  bogomips: 31872 
  Speed: 900 MHz min/max: 400/4000 MHz base/boost: 3700/1800 volts: 1.1 V 
  ext-clock: 100 MHz Core speeds (MHz): 1: 900 2: 900 3: 901 4: 900 5: 900 
  6: 900 7: 900 8: 900 
  Vulnerabilities: Type: itlb_multihit status: KVM: Split huge pages 
  Type: l1tf 
  mitigation: PTE Inversion; VMX: conditional cache flushes, SMT vulnerable 
  Type: mds mitigation: Clear CPU buffers; SMT vulnerable 
  Type: meltdown mitigation: PTI 
  Type: spec_store_bypass 
  mitigation: Speculative Store Bypass disabled via prctl and seccomp 
  Type: spectre_v1 
  mitigation: usercopy/swapgs barriers and __user pointer sanitization 
  Type: spectre_v2 mitigation: Full generic retpoline, IBPB: conditional, 
  IBRS_FW, STIBP: conditional, RSB filling 
  Type: srbds mitigation: Microcode 
  Type: tsx_async_abort status: Not affected 
Graphics:
  Device-1: Intel UHD Graphics 620 vendor: Dell driver: i915 v: kernel 
  bus-ID: 00:02.0 chip-ID: 8086:5917 class-ID: 0300 
  Device-2: Realtek Integrated_Webcam_HD type: USB driver: uvcvideo 
  bus-ID: 1-5:2 chip-ID: 0bda:58f4 class-ID: 0e02 serial: <filter> 
  Display: server: X.Org 1.20.13 compositor: kwin_x11 driver: 
  loaded: modesetting alternate: fbdev,vesa display-ID: :0 screens: 1 
  Screen-1: 0 s-res: 1920x1080 s-dpi: 96 s-size: 508x285mm (20.0x11.2") 
  s-diag: 582mm (22.9") 
  Monitor-1: eDP-1 res: 1920x1080 hz: 60 dpi: 166 size: 294x165mm (11.6x6.5") 
  diag: 337mm (13.3") 
  OpenGL: renderer: Mesa Intel UHD Graphics 620 (KBL GT2) v: 4.6 Mesa 21.2.2 
  direct render: Yes 
Audio:
  Device-1: Intel Sunrise Point-LP HD Audio vendor: Dell driver: snd_hda_intel 
  v: kernel alternate: snd_soc_skl bus-ID: 00:1f.3 chip-ID: 8086:9d71 
  class-ID: 0403 
  Sound Server-1: ALSA v: k4.19.207-1-MANJARO running: yes 
  Sound Server-2: JACK v: 1.9.19 running: no 
  Sound Server-3: PulseAudio v: 15.0 running: yes 
  Sound Server-4: PipeWire v: 0.3.37 running: no 
Network:
  Device-1: Qualcomm Atheros QCA6174 802.11ac Wireless Network Adapter 
  vendor: Rivet Networks Killer 1435 Wireless-AC driver: ath10k_pci v: kernel 
  port: f040 bus-ID: 02:00.0 chip-ID: 168c:003e class-ID: 0280 
  IF: wlp2s0 state: up mac: <filter> 
  IF-ID-1: br-1cd3b4553ed9 state: down mac: <filter> 
  IF-ID-2: docker0 state: down mac: <filter> 
Bluetooth:
  Device-1: Foxconn / Hon Hai type: USB driver: btusb v: 0.8 bus-ID: 1-7:3 
  chip-ID: 0489:e0a2 class-ID: e001 
  Report: rfkill ID: hci0 rfk-id: 1 state: down bt-service: enabled,running 
  rfk-block: hardware: no software: yes address: see --recommends 
Drives:
  Local Storage: total: 596.19 GiB used: 74.63 GiB (12.5%) 
  ID-1: /dev/mmcblk0 maj-min: 179:0 vendor: Samsung model: ED4QT 
  size: 119.25 GiB block-size: physical: 512 B logical: 512 B type: SSD 
  serial: <filter> scheme: MBR 
  SMART Message: Unknown smartctl error. Unable to generate data. 
  ID-2: /dev/nvme0n1 maj-min: 259:0 vendor: Toshiba 
  model: KXG50ZNV512G NVMe 512GB size: 476.94 GiB block-size: physical: 512 B 
  logical: 512 B speed: 31.6 Gb/s lanes: 4 type: SSD serial: <filter> 
  rev: AADA4102 temp: 46 Celsius C scheme: MBR 
  SMART: yes health: PASSED on: 50d 12h cycles: 1,264 
  read-units: 2,678,106 [1.37 TB] written-units: 4,194,902 [2.14 TB] 
Partition:
  ID-1: / raw-size: 476.93 GiB size: 468.45 GiB (98.22%) 
  used: 74.63 GiB (15.9%) fs: ext4 block-size: 4096 B dev: /dev/nvme0n1p1 
  maj-min: 259:1 
Swap:
  Alert: No swap data was found. 
Sensors:
  System Temperatures: cpu: 45.0 C mobo: N/A 
  Fan Speeds (RPM): N/A 
Info:
  Processes: 209 Uptime: 0m wakeups: 92 Memory: 7.61 GiB 
  used: 1.12 GiB (14.7%) Init: systemd v: 249 tool: systemctl Compilers: 
  gcc: 11.1.0 clang: 12.0.1 Packages: pacman: 1457 lib: 422 flatpak: 0 
  Shell: Bash (sudo) v: 5.1.8 running-in: yakuake inxi: 3.3.06 

inxi -mxx output:

Memory:    RAM: total: 7.61 GiB used: 1.12 GiB (14.8%) 
           Array-1: capacity: 16 GiB slots: 2 EC: None max-module-size: 8 GiB note: est. 
           Device-1: System Board Memory size: 8 GiB speed: 2133 MT/s type: LPDDR3 manufacturer: Micron 
           part-no: MT52L1G32D4PG-093 
           Device-2: System Board Memory size: 8 GiB speed: 2133 MT/s type: LPDDR3 manufacturer: Micron 
           part-no: MT52L1G32D4PG-093 

Memtest appears to only test for 8008M of RAM, but in the DMI Memory Device Info screen, reports two RAM units:

System Board → Memor8192 → 2133MHz → LPDDR3 → Row of chips
Mapped to
000000000000 - 0001ffffffff

System Board → Memor8192 → 2133MHz → LPDDR3 → Row of chips
Mapped to
000200000000 - 0003ffffffff

Any help is appreciated, though I suspect my RAM is just dead and now I have an irreparable half RAM machine. Sorry for posting little memtest data, I cannot include links or images.

Welcome to the forum! :wave:

Have you tried reseating the RAM module?

Don’t think it’s feasible, because of,

If memtest only reads one 8GB stick, I’d err towards a bad stick and/or memory controller and/or motherboard. (Or even though it is soldered, it somehow got “loose”.)

Oh, I thought only one module was soldered as that’s the usual case.

Quite possibly.

Is the machine still covered under warranty and/or extended coverage? Otherwise, you might in fact be correct about your situation. :confused:

This one is peculiar. It reads both sticks, 8 + 8, but then claims your RAM total is only 8.

Still, could be bad RAM.

If you run sudo dmidecode, do you see two separate sticks listed?

Look for two entries that are similar to this format:

Handle 0x0042, DMI type 20, 35 bytes
Memory Device Mapped Address
	Starting Address: 0x00000000000
	Ending Address: 0x000FFFFFFFF
	Range Size: 4 GB
	Physical Device Handle: 0x003E
	Memory Array Mapped Address Handle: 0x0033
	Partition Row Position: Unknown
	Interleave Position: 1
	Interleaved Data Depth: 2

Handle 0x0043, DMI type 20, 35 bytes
Memory Device Mapped Address
	Starting Address: 0x00100000000
	Ending Address: 0x002FFFFFFFF
	Range Size: 8 GB
	Physical Device Handle: 0x0040
	Memory Array Mapped Address Handle: 0x0033
	Partition Row Position: Unknown
	Interleave Position: 2
	Interleaved Data Depth: 2

The above is an example of two entries next to each other, that display an 8GB stick and a 4GB stick (my usable RAM is 12GB for this machine.)

Thanks for the prompt response, I do think I may be out of luck as the warranty expired a few years ago.

The output that I believe you are interested in is here:

Handle 0x0044, DMI type 20, 35 bytes
Memory Device Mapped Address
        Starting Address: 0x00000000000
        Ending Address: 0x001FFFFFFFF
        Range Size: 8 GB
        Physical Device Handle: 0x003D
        Memory Array Mapped Address Handle: 0x003F
        Partition Row Position: 1
        Interleave Position: 1
        Interleaved Data Depth: 1

Handle 0x0045, DMI type 20, 35 bytes
Memory Device Mapped Address
        Starting Address: 0x00200000000
        Ending Address: 0x003FFFFFFFF
        Range Size: 8 GB
        Physical Device Handle: 0x003E
        Memory Array Mapped Address Handle: 0x003F
        Partition Row Position: 1
        Interleave Position: 2
        Interleaved Data Depth: 1

This is why I find it so bizarre, perhaps I should open up the machine and try pushing on the soldered RAM modules a little… but doubt that would do anything.

Thanks for the welcome :slight_smile: I believe I am unlucky in that both modules are soldered

So I figured out the issue after digging deep into it with a colleague. Memtest showed that it would go into the 10-11GiB range even though it detected at most 8GiB.
I found that somebody with my same hardware had an issue where they could UEFI boot and see more RAM available, so I burned an Arch iso to a micro sd card and booted off of that in UEFI - and free -h reported 15 gigs available.

I am happy and relieved and also slightly annoyed, so I guess I will have to go through some work of making a UEFI partition and figuring out how to link my existing OS with it.

Either that, or using this as an opportunity to learn Linux at it’s core and install Arch via the iso and set it up myself.

Thanks for the help, and I hope somebody finds this thread someday and that it helps them.

I have never heard of that before. Depending on how you boot (MBR vs UEFI) dictates how much RAM is available? :astonished: Maybe for certain HP laptops? That’s so bizarre.

Most bizarre thing I’ve come across in computing, if it interests anyone I could always provide some images/vids of the bizarre behaviour…
I picked XPS because of how well they work with Linux, but I couldn’t tell you how MBR vs UEFI changed the RAM available; guess I’ll do UEFI everything in the future.

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