Asus Pro WS 621-64L SAGE Series Manual page 45

18. VPP_I2C1 connector (Pro WS C621-64L SAGE/10G only)
The VPP_I2C1 connector is used for the storage backplane with Intel VMD function
and sensor readings.
19. System Management Bus connector
The System Management Bus (SMBus) connector allows you to connect SMBus
devices. This connector is generally used for communication with the system and
power management-related tasks.
ASUS Pro WS C621-64L SAGE Series
1-31