Question 1/2 of memory recognized on Z790?

[hankbrandenburg]

I put together a machine with a Z790 motherboard, i9 CPU and 4 32 GB DDR 5 RAM cards. The machine boots Debian and runs reliably; however only 16 GB of RAM is recognized on the two RAM cards in the A1/A2 slots. Not sure what is causing this. dmidecode info is below; any ideas appreciated!


sudo dmidecode -t 2
# dmidecode 3.4
Getting SMBIOS data from sysfs.
SMBIOS 3.6.0 present.
# SMBIOS implementations newer than version 3.5.0 are not
# fully supported by this version of dmidecode.

Handle 0x0002, DMI type 2, 15 bytes
Base Board Information
Manufacturer: Gigabyte Technology Co., Ltd.
Product Name: Z790 AORUS ELITE AX
Version: x.x
Serial Number: Default string
Asset Tag: Default string
Features:
Board is a hosting board
Board is replaceable
Location In Chassis: Default string
Chassis Handle: 0x0003
Type: Motherboard
Contained Object Handles: 0

sudo dmidecode -t 17
# dmidecode 3.4
Getting SMBIOS data from sysfs.
SMBIOS 3.6.0 present.
# SMBIOS implementations newer than version 3.5.0 are not
# fully supported by this version of dmidecode.

Handle 0x003C, DMI type 17, 92 bytes
Memory Device
Array Handle: 0x003B
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 16 GB
Form Factor: DIMM
Set: None
Locator: DDR5-A1
Bank Locator: BANK 0
Type: DDR5
Type Detail: Synchronous
Speed: 4800 MT/s
Manufacturer: G Skill Intl
Serial Number: 4A59DFF0
Asset Tag: 9876543210
Part Number: F5-6400J3239G16G
Rank: 1
Configured Memory Speed: 4000 MT/s
Minimum Voltage: 1.0 V
Maximum Voltage: 1.4 V
Configured Voltage: 1.1 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Not Specified
Module Manufacturer ID: Bank 5, Hex 0xCD
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 0x003D, DMI type 17, 92 bytes
Memory Device
Array Handle: 0x003B
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 16 GB
Form Factor: DIMM
Set: None
Locator: DDR5-A2
Bank Locator: BANK 0
Type: DDR5
Type Detail: Synchronous
Speed: 4800 MT/s
Manufacturer: G Skill Intl
Serial Number: 2C5C3BF4
Asset Tag: 9876543210
Part Number: F5-6400J3239G16G
Rank: 1
Configured Memory Speed: 4000 MT/s
Minimum Voltage: 1.0 V
Maximum Voltage: 1.4 V
Configured Voltage: 1.1 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Not Specified
Module Manufacturer ID: Bank 5, Hex 0xCD
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 0x003E, DMI type 17, 92 bytes
Memory Device
Array Handle: 0x003B
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 32 GB
Form Factor: DIMM
Set: None
Locator: DDR5-B1
Bank Locator: BANK 0
Type: DDR5
Type Detail: Synchronous
Speed: 4800 MT/s
Manufacturer: G Skill Intl
Serial Number: 515F87F2
Asset Tag: 9876543210
Part Number: F5-6400J3239G32G
Rank: 2
Configured Memory Speed: 4000 MT/s
Minimum Voltage: 1.0 V
Maximum Voltage: 1.4 V
Configured Voltage: 1.1 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Not Specified
Module Manufacturer ID: Bank 5, Hex 0xCD
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

Handle 0x003F, DMI type 17, 92 bytes
Memory Device
Array Handle: 0x003B
Error Information Handle: Not Provided
Total Width: 64 bits
Data Width: 64 bits
Size: 32 GB
Form Factor: DIMM
Set: None
Locator: DDR5-B2
Bank Locator: BANK 0
Type: DDR5
Type Detail: Synchronous
Speed: 4800 MT/s
Manufacturer: G Skill Intl
Serial Number: 705660F3
Asset Tag: 9876543210
Part Number: F5-6400J3239G32G
Rank: 2
Configured Memory Speed: 4000 MT/s
Minimum Voltage: 1.0 V
Maximum Voltage: 1.4 V
Configured Voltage: 1.1 V
Memory Technology: DRAM
Memory Operating Mode Capability: Volatile memory
Firmware Version: Not Specified
Module Manufacturer ID: Bank 5, Hex 0xCD
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

 

[Lutfij]

Welcome to the forums, newcomer!

I don't see mention of what BIOS version you're on for your motherboard. Upon further digging, I noticed Gigabyte have two PCB revision numbers;
https://www.gigabyte.com/Motherboard/Z790-AORUS-ELITE-AX-rev-10/support#dl
the other being rev 1.x apart from rev 1.0

Can you also try putting two sticks of ram in slots A2 and B2, per the manual? If you don't see the ram show up in BIOS in spite of the sticks being fully seated, have the latest BIOS version and cleared your CMOS, then it's possible that your memory controller for channel B gave up.

 

[dwd999]

I put together a machine with a Z790 motherboard, i9 CPU and 4 32 GB DDR 5 RAM cards.

Part Number: F5-6400J3239G16G

Volatile Size: 16 GB

Part Number: F5-6400J3239G16G

Volatile Size: 16 GB
Part Number: F5-6400J3239G32G

Volatile Size: 32 GB

Part Number: F5-6400J3239G32G

No, the part number F5-6400J3239G16G for the first 2 sticks clearly indicates that it is a 16GB stick. You have 2 16GB sticks and 2 32GB sticks. Do the internal part numbers shown above match the external packaging and labelling? If not, someone has deceived you.

 

[geofelt]

You will get more and better answers if you list the make/model of your specs simply.