Unable to check if memory is running in dual-channel mode
by MirceaKitsune from LinuxQuestions.org on (#5M6CT)
Some background first: When I built my latest system two years ago and got a DDR4 motherboard I bought 16 GB of RAM (2 x 8 GB). Today I had the money to finally order another set, identical to the first one so that all 4 memory modules are the exact same model in every way. I just installed them and everything works fine, I have 32 GB of memory and the system even feels a little faster.
Still I wanted to make sure the system is running in dual-channel mode given I never used all 4 memory slots before. The BIOS doesn't seem to inform me. I looked up the Linux command commonly used to verify, but for some odd reason it doesn't appear to give me a clear verdict.
Code:[linux-qz0r mircea]# dmidecode -t 17
# dmidecode 3.3
Getting SMBIOS data from sysfs.
SMBIOS 3.1.1 present.
Handle 0x0034, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x002C
Error Information Handle: 0x0033
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: DIMM
Set: None
Locator: DIMM_A1
Bank Locator: BANK 0
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Kingston
Serial Number: 89FA951F
Asset Tag: Not Specified
Part Number: KHX3200C16D4/8GX
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 V
Handle 0x0037, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x002C
Error Information Handle: 0x0036
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: DIMM
Set: None
Locator: DIMM_A2
Bank Locator: BANK 1
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Kingston
Serial Number: B74E32EC
Asset Tag: Not Specified
Part Number: KHX3200C16D4/8GX
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 V
Handle 0x003A, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x002C
Error Information Handle: 0x0039
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: DIMM
Set: None
Locator: DIMM_B1
Bank Locator: BANK 2
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Kingston
Serial Number: 89FA90A7
Asset Tag: Not Specified
Part Number: KHX3200C16D4/8GX
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 V
Handle 0x003D, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x002C
Error Information Handle: 0x003C
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: DIMM
Set: None
Locator: DIMM_B2
Bank Locator: BANK 3
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Kingston
Serial Number: AD8E3007
Asset Tag: Not Specified
Part Number: KHX3200C16D4/8GX
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 VI understand my locator should be something like ChannelA-DIMM0 but instead I have ones like DIMM_A1. Does this indicate there might be a problem and I could be on single channel? Could that happen even when all memory modules are identical in every way? How do I check with certainty?
Still I wanted to make sure the system is running in dual-channel mode given I never used all 4 memory slots before. The BIOS doesn't seem to inform me. I looked up the Linux command commonly used to verify, but for some odd reason it doesn't appear to give me a clear verdict.
Code:[linux-qz0r mircea]# dmidecode -t 17
# dmidecode 3.3
Getting SMBIOS data from sysfs.
SMBIOS 3.1.1 present.
Handle 0x0034, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x002C
Error Information Handle: 0x0033
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: DIMM
Set: None
Locator: DIMM_A1
Bank Locator: BANK 0
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Kingston
Serial Number: 89FA951F
Asset Tag: Not Specified
Part Number: KHX3200C16D4/8GX
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 V
Handle 0x0037, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x002C
Error Information Handle: 0x0036
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: DIMM
Set: None
Locator: DIMM_A2
Bank Locator: BANK 1
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Kingston
Serial Number: B74E32EC
Asset Tag: Not Specified
Part Number: KHX3200C16D4/8GX
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 V
Handle 0x003A, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x002C
Error Information Handle: 0x0039
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: DIMM
Set: None
Locator: DIMM_B1
Bank Locator: BANK 2
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Kingston
Serial Number: 89FA90A7
Asset Tag: Not Specified
Part Number: KHX3200C16D4/8GX
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 V
Handle 0x003D, DMI type 17, 40 bytes
Memory Device
Array Handle: 0x002C
Error Information Handle: 0x003C
Total Width: 64 bits
Data Width: 64 bits
Size: 8 GB
Form Factor: DIMM
Set: None
Locator: DIMM_B2
Bank Locator: BANK 3
Type: DDR4
Type Detail: Synchronous Unbuffered (Unregistered)
Speed: 3200 MT/s
Manufacturer: Kingston
Serial Number: AD8E3007
Asset Tag: Not Specified
Part Number: KHX3200C16D4/8GX
Rank: 1
Configured Memory Speed: 3200 MT/s
Minimum Voltage: 1.2 V
Maximum Voltage: 1.2 V
Configured Voltage: 1.2 VI understand my locator should be something like ChannelA-DIMM0 but instead I have ones like DIMM_A1. Does this indicate there might be a problem and I could be on single channel? Could that happen even when all memory modules are identical in every way? How do I check with certainty?