Unit Queries#

This chapter describes that queries that NVML can perform against each unit.

For S-class systems only. In each case the device is identified with an nvmlUnit_t handle. This handle is obtained by calling nvmlUnitGetHandleByIndex().

Functions#

nvmlReturn_t nvmlUnitGetCount(unsigned int *unitCount)

Retrieves the number of units in the system.

nvmlReturn_t nvmlUnitGetDevices(nvmlUnit_t unit, unsigned int *deviceCount, nvmlDevice_t *devices)

Retrieves the set of GPU devices that are attached to the specified unit.

nvmlReturn_t nvmlUnitGetFanSpeedInfo(nvmlUnit_t unit, nvmlUnitFanSpeeds_t *fanSpeeds)

Retrieves the fan speed readings for the unit.

nvmlReturn_t nvmlUnitGetHandleByIndex(unsigned int index, nvmlUnit_t *unit)

Acquire the handle for a particular unit, based on its index.

nvmlReturn_t nvmlUnitGetLedState(nvmlUnit_t unit, nvmlLedState_t *state)

Retrieves the LED state associated with this unit.

nvmlReturn_t nvmlUnitGetPsuInfo(nvmlUnit_t unit, nvmlPSUInfo_t *psu)

Retrieves the PSU stats for the unit.

nvmlReturn_t nvmlUnitGetTemperature(nvmlUnit_t unit, unsigned int type, unsigned int *temp)

Retrieves the temperature readings for the unit, in degrees C.

nvmlReturn_t nvmlUnitGetUnitInfo(nvmlUnit_t unit, nvmlUnitInfo_t *info)

Retrieves the static information associated with a unit.

Functions#

nvmlReturn_t nvmlUnitGetCount(unsigned int *unitCount)#

Retrieves the number of units in the system.

For S-class products.

Parameters:

unitCount – Reference in which to return the number of units

Returns:

nvmlReturn_t nvmlUnitGetDevices(
nvmlUnit_t unit,
unsigned int *deviceCount,
nvmlDevice_t *devices,
)#

Retrieves the set of GPU devices that are attached to the specified unit.

For S-class products.

The deviceCount argument is expected to be set to the size of the input devices array.

Parameters:
  • unit – The identifier of the target unit

  • deviceCount – Reference in which to provide the devices array size, and to return the number of attached GPU devices

  • devices – Reference in which to return the references to the attached GPU devices

Returns:

nvmlReturn_t nvmlUnitGetFanSpeedInfo(
nvmlUnit_t unit,
nvmlUnitFanSpeeds_t *fanSpeeds,
)#

Retrieves the fan speed readings for the unit.

For S-class products.

See nvmlUnitFanSpeeds_t for details on available fan speed info.

Parameters:
  • unit – The identifier of the target unit

  • fanSpeeds – Reference in which to return the fan speed information

Returns:

nvmlReturn_t nvmlUnitGetHandleByIndex(
unsigned int index,
nvmlUnit_t *unit,
)#

Acquire the handle for a particular unit, based on its index.

For S-class products.

Valid indices are derived from the unitCount returned by nvmlUnitGetCount(). For example, if unitCount is 2 the valid indices are 0 and 1, corresponding to UNIT 0 and UNIT 1.

The order in which NVML enumerates units has no guarantees of consistency between reboots.

Parameters:
  • index – The index of the target unit, >= 0 and < unitCount

  • unit – Reference in which to return the unit handle

Returns:

nvmlReturn_t nvmlUnitGetLedState(
nvmlUnit_t unit,
nvmlLedState_t *state,
)#

Retrieves the LED state associated with this unit.

For S-class products.

See nvmlLedState_t for details on allowed states.

Parameters:
  • unit – The identifier of the target unit

  • state – Reference in which to return the current LED state

Returns:

nvmlReturn_t nvmlUnitGetPsuInfo(nvmlUnit_t unit, nvmlPSUInfo_t *psu)#

Retrieves the PSU stats for the unit.

For S-class products.

See nvmlPSUInfo_t for details on available PSU info.

Parameters:
  • unit – The identifier of the target unit

  • psu – Reference in which to return the PSU information

Returns:

nvmlReturn_t nvmlUnitGetTemperature(
nvmlUnit_t unit,
unsigned int type,
unsigned int *temp,
)#

Retrieves the temperature readings for the unit, in degrees C.

For S-class products.

Depending on the product, readings may be available for intake (type=0), exhaust (type=1) and board (type=2).

Parameters:
  • unit – The identifier of the target unit

  • type – The type of reading to take

  • temp – Reference in which to return the intake temperature

Returns:

nvmlReturn_t nvmlUnitGetUnitInfo(
nvmlUnit_t unit,
nvmlUnitInfo_t *info,
)#

Retrieves the static information associated with a unit.

For S-class products.

See nvmlUnitInfo_t for details on available unit info.

Parameters:
  • unit – The identifier of the target unit

  • info – Reference in which to return the unit information

Returns: