Hi. I have a ThinkPad P14s Gen 2a with AMD Ryzen 7 PRO 5850U and 2 RAM modules:
* built-in 16 GB
* additional 32 GB
I do know that, in order to get dual channel working, the best bet is for the memory modules to be "as equal as possible" (size, frequencies/timings, vendor etc.), and it's definitely not the case I have.
But, anyway, now I'm curious
how can I check for sure, do I have double channel or not... And turns out it's not that simple, because I find many conflicting sources of information around the Internet.
Also, I've found some pieces of information like "if your memory modules have different sizes, dual channel can be active for some part of RAM, but not for all of it"... sounds strange to me, but, again, no idea if that's true and how can I check it.
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Code:
$ sudo dmidecode -t 17
Place your right index finger on the fingerprint reader
# dmidecode 3.3
Getting SMBIOS data from sysfs.
SMBIOS 3.3.0 present.
Handle 0x0008, DMI type 17, 92 bytes
Memory Device
Array Handle: 0x0001
Error Information Handle: 0x0007
Total Width: 64 bits
Data Width: 64 bits
Size: 16 GB
Form Factor: SODIMM
Set: None
Locator: DIMM 0
Bank Locator: P0 CHANNEL A
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Micron Technology
Serial Number: 00000000
Asset Tag: Not Specified
Part Number: 4ATS2G64HZ-3G2B1
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Unknown
Module Manufacturer ID: Bank 1, Hex 0x2C
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 0x000B, DMI type 17, 92 bytes
Memory Device
Array Handle: 0x0001
Error Information Handle: 0x000A
Total Width: 64 bits
Data Width: 64 bits
Size: 32 GB
Form Factor: SODIMM
Set: None
Locator: DIMM 0
Bank Locator: P0 CHANNEL B
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Samsung
Serial Number: 32072E4E
Asset Tag: Not Specified
Part Number: M471A4G43AB1-CWE
Rank: 2
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Unknown
Module Manufacturer ID: Bank 1, Hex 0xCE
Module Product ID: Unknown
Memory Subsystem Controller Manufacturer ID: Unknown
Memory Subsystem Controller Product ID: Unknown
Non-Volatile Size: None
Volatile Size: 32 GB
Cache Size: None
Logical Size: None
Code:
$ sudo lshw -C memory
*-memory
description: System Memory
physical id: 1
slot: System board or motherboard
size: 48GiB
*-bank:0
description: SODIMM DDR4 Synchronous Unbuffered (Unregistered) 3200 MHz (0,3 ns)
product: 4ATS2G64HZ-3G2B1
vendor: Micron Technology
physical id: 0
serial: 00000000
slot: DIMM 0
size: 16GiB
width: 64 bits
clock: 3200MHz (0.3ns)
*-bank:1
description: SODIMM DDR4 Synchronous Unbuffered (Unregistered) 3200 MHz (0,3 ns)
product: M471A4G43AB1-CWE
vendor: Samsung
physical id: 1
serial: 32072E4E
slot: DIMM 0
size: 32GiB
width: 64 bits
clock: 3200MHz (0.3ns)
*-cache:0
description: L1 cache
physical id: 3
slot: L1 - Cache
size: 512KiB
capacity: 512KiB
clock: 1GHz (1.0ns)
capabilities: pipeline-burst internal write-back unified
configuration: level=1
*-cache:1
description: L2 cache
physical id: 4
slot: L2 - Cache
size: 4MiB
capacity: 4MiB
clock: 1GHz (1.0ns)
capabilities: pipeline-burst internal write-back unified
configuration: level=2
*-cache:2
description: L3 cache
physical id: 5
slot: L3 - Cache
size: 16MiB
capacity: 16MiB
clock: 1GHz (1.0ns)
capabilities: pipeline-burst internal write-back unified
configuration: level=3
*-firmware
description: BIOS
vendor: LENOVO
physical id: e
version: R1MET54W (1.24 )
date: 05/15/2023
size: 128KiB
capacity: 32MiB
capabilities: pci pnp upgrade shadowing cdboot bootselect edd int13floppy720 int5printscreen int9keyboard int14serial int17printer int10video acpi usb biosbootspecification uefi
... and, since some replies I've found mentioned something about "this can be checked only if you run memtest86+" - a photo of the running memtest86+, just in case (see attached "memtest.jpg")
