Answer by kucer for detect number of RAM channels

I tried out dmidecode

dmidecode -t memory

Fortunately, the row Bank Locator: SOCKET 1 CHANNEL 7 DIMM 0 tell DIMM 170 was in Channel 7. And the machine support 32 DIMM with total 8 channels. The corresponding channels listed bellow:

Handle 0x0026, DMI type 17, 40 bytes
Memory Device
        Array Handle: 0x0006
        Error Information Handle: Not Provided
        Total Width: 72 bits
        Data Width: 64 bits
        Size: 32 GB
        Form Factor: DIMM
        Set: None
        Locator: DIMM170 J31
        Bank Locator: SOCKET 1 CHANNEL 7 DIMM 0
        Type: DDR4
        Type Detail: Synchronous Registered (Buffered)
        Speed: 2666 MT/s
        Manufacturer: Samsung
        Serial Number: 0x40C3BA1D
        Asset Tag: 1838
        Part Number: M393A4K40BB2-CTD
        Rank: 2
        Configured Clock Speed: 2666 MT/s
        Minimum Voltage: 1.2 V
        Maximum Voltage: 2.0 V
        Configured Voltage: 1.2 V

[user@centos ~]$ sudo dmidecode -t memory | grep CHANNEL
        Bank Locator: SOCKET 0 CHANNEL 0 DIMM 0
        Bank Locator: SOCKET 0 CHANNEL 0 DIMM 1
        Bank Locator: SOCKET 0 CHANNEL 1 DIMM 0
        Bank Locator: SOCKET 0 CHANNEL 1 DIMM 1
        Bank Locator: SOCKET 0 CHANNEL 2 DIMM 0
        Bank Locator: SOCKET 0 CHANNEL 2 DIMM 1
        Bank Locator: SOCKET 0 CHANNEL 3 DIMM 0
        Bank Locator: SOCKET 0 CHANNEL 3 DIMM 1
        Bank Locator: SOCKET 0 CHANNEL 4 DIMM 0
        Bank Locator: SOCKET 0 CHANNEL 4 DIMM 1
        Bank Locator: SOCKET 0 CHANNEL 5 DIMM 0
        Bank Locator: SOCKET 0 CHANNEL 5 DIMM 1
        Bank Locator: SOCKET 0 CHANNEL 6 DIMM 0
        Bank Locator: SOCKET 0 CHANNEL 6 DIMM 1
        Bank Locator: SOCKET 0 CHANNEL 7 DIMM 0
        Bank Locator: SOCKET 0 CHANNEL 7 DIMM 1
        Bank Locator: SOCKET 1 CHANNEL 0 DIMM 0
        Bank Locator: SOCKET 1 CHANNEL 0 DIMM 1
        Bank Locator: SOCKET 1 CHANNEL 1 DIMM 0
        Bank Locator: SOCKET 1 CHANNEL 1 DIMM 1
        Bank Locator: SOCKET 1 CHANNEL 2 DIMM 0
        Bank Locator: SOCKET 1 CHANNEL 2 DIMM 1
        Bank Locator: SOCKET 1 CHANNEL 3 DIMM 0
        Bank Locator: SOCKET 1 CHANNEL 3 DIMM 1
        Bank Locator: SOCKET 1 CHANNEL 4 DIMM 0
        Bank Locator: SOCKET 1 CHANNEL 4 DIMM 1
        Bank Locator: SOCKET 1 CHANNEL 5 DIMM 0
        Bank Locator: SOCKET 1 CHANNEL 5 DIMM 1
        Bank Locator: SOCKET 1 CHANNEL 6 DIMM 0
        Bank Locator: SOCKET 1 CHANNEL 6 DIMM 1
        Bank Locator: SOCKET 1 CHANNEL 7 DIMM 0
        Bank Locator: SOCKET 1 CHANNEL 7 DIMM 1