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
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