Question get total memory, but dual channel doesn't work

[dubeux]

I recently bought a Thinkpad L14 intel G2 20X2006PBO, with an i5-1135G7.
It comes with 8 GB of RAM. I removed it and installed 2x 16 GB sticks - same brand (Crucial), same model.
I do get 32 GB, but dual channel doesn't seem to be working. I'm running linux (Manjaro).
I've swapped the sticks, got the same results.
Apparently, it has one only memory bank/channel, while having two working slots/controllers. Am I missing something? Is it normal?

dmidecode -t memory | grep Bank
Bank Locator: BANK 0
Module Manufacturer ID: Bank 6, Hex 0x9B
Bank Locator: BANK 0
Module Manufacturer ID: Bank 6, Hex 0x9B

dmidecode -t 17
Getting SMBIOS data from sysfs.
SMBIOS 3.2.0 present.
Handle 0x0002, DMI type 17, 92 bytes
Memory Device
Array Handle: 0x0001
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 16 GB
Form Factor: SODIMM
Set: None
Locator: Controller0-ChannelA-DIMM0
Bank Locator: BANK 0
Type: DDR4
Type Detail: Synchronous
Speed: 3200 MT/s
Manufacturer: Crucial Technology
Asset Tag: None
Part Number: CT16G4SFS832A
Rank: 2
Configured Memory Speed: 3200 MT/s
Minimum Voltage: Unknown
Maximum Voltage: Unknown
Configured Voltage: 1.2 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Not Specified
Module Manufacturer ID: Bank 6, Hex 0x9B
Module Product ID: Unknown
Memory Subsystem Controller Manufacturer ID: Unknown
Memory Subsystem Controller Product ID: Unknown
Non-Volatile Size: None
Volatile Size: 16 GB
Cache Size: None
Logical Size: None

Handle 0x0003, DMI type 17, 92 bytes
Memory Device
Array Handle: 0x0001
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 16 GB
Form Factor: SODIMM
Set: None
Locator: Controller1-ChannelA-DIMM0
Bank Locator: BANK 0
Type: DDR4
Type Detail: Synchronous
Speed: 3200 MT/s
Manufacturer: Crucial Technology
Asset Tag: None
Part Number: CT16G4SFS832A
Rank: 2
Configured Memory Speed: 3200 MT/s
Minimum Voltage: Unknown
Maximum Voltage: Unknown
Configured Voltage: 1.2 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Not Specified
Module Manufacturer ID: Bank 6, Hex 0x9B
Module Product ID: Unknown
Memory Subsystem Controller Manufacturer ID: Unknown
Memory Subsystem Controller Product ID: Unknown
Non-Volatile Size: None
Volatile Size: 16 GB
Cache Size: None
Logical Size: None

 

[Lutfij]

Welcome to the forums, newcomer!

https://psref.lenovo.com/Detail/ThinkPad_L14_Gen_2_Intel?M=20X2006PBO
^ According to that, it says dual channel capable and your data above shows that two controllers are being taxed/recognized...you're in good order.

Just curious, might want to check and see if your laptop has BIOS updates pending. This is a good read and similar instance.

 

[dubeux]

Thank you for the welcome and the answer.
Yes, the machine is supposed to be dual channel capable, and I've updated the BIOS. My question is, as usual, based on my ignorance: in the link you sent, someone says "The locators in your output differ in controller, not channel. I suspect that can be taken as a hint to different 'paths' aka dual-channel being used".
As this guy hints, he doesn't actually know (as myself) exactly what is a memory controller. Is it possible to have dual channel with 2 controllers, in the same channel? If so, how could I verify it's running in dual channel?

 

[geofelt]

At one time ram controllers were separate chips on the motherboard.
Intel processors changed that by incorporating ram control within the processor ship itself.
If you have two sticks of ram and only two places for the sticks, you most assuredly are running dual channel, barring a cpu defect(which is extremely rare) or a motherboard socket defect.
Run CPU-Z.
On the memory tab, on the upper right, it should say 2 x 64 bit
On the spd tab, you will have an entry describing what is populated in each slot.
You should see slot#1 and slot#2 with details about the stick that is there.
They should be identical.

 

[COLGeek]

Linux has CPU-X, not CPU-Z.

CPU-X

CPU-X is a Free software that gathers information on CPU, motherboard and more.

thetumultuousunicornofdarkness.github.io

 

[geofelt]

Linux has CPU-X, not CPU-Z.

CPU-X

CPU-X is a Free software that gathers information on CPU, motherboard and more.

thetumultuousunicornofdarkness.github.io

It is not clear to me that his is a linux based system.
No matter.
I imagine that CPU-X would provide similar information.

 

[dubeux]

It seems to be weirdly hard, to find out actual info about dual channel in Linux. Cpu-x doesn't help. This machine's BIOS has nothing about RAM.
I ended up finding an option in the boot menu, Lenovo diagnostics, saying I'm running in single channel mode. Which, of course is quite puzzling - I can't imagine what could I do to get dual channel.
I'll try to reach Lenovo, see if they can be of any help - though I'm not very hopeful.

Memory Channel Mode: Single
Total Physical Memory: 32768 MB
   
Origin: SMBIOS
Type: DDR4
Manufacturer: Crucial Technology
Maximum Speed: 3200 MT/s
Current Speed: 3200 MT/s
Size: 16384 MB
Bank Locator: BANK 0
Device Locator: Controller0-ChannelA-DIMM0
Part Number: CT16G4SFS832A
   
Origin: SMBIOS
Type: DDR4
Manufacturer: Crucial Technology
Maximum Speed: 3200 MT/s
Current Speed: 3200 MT/s
Size: 16384 MB
Bank Locator: BANK 0
Device Locator: Controller1-ChannelA-DIMM0
Part Number: CT16G4SFS832A

 

[COLGeek]

Is your system (motherboard) BIOS/firmware fully up to date?

 

[dubeux]

Yes, I updated the bios.

 

[COLGeek]

Yes, I updated the bios.

With all of the memory installed, or before?

 

[dubeux]

Before

 

[COLGeek]

Do you have a link for the exact memory you installed?

 

[dubeux]

No, Crucial says it has been replaced. It's the CT16G4SFS832A.