Asus P8B-MX - Manual (Page 51)

ASUS P8B-M series 2-33
9. Power Supply SMBus connector (5-pin PSUSMB1)
This connector allows you to connect SMBus (System Management Bus) to
the power supply unit to read PSU information. Devices communicate with an
SMBus host and/or other SMBus devices using the SMBus interface.
This connector functions only when you install the ASUS ASMB5.
10. TPM connector (20-1 pin TPM)
This connector supports a Trusted Platform Module (TPM) system, which can
securely store keys, digital certificates, passwords, and data. A TPM system
also helps enhance network security, protects digital identities, and ensures
platform integrity.