Server Board Family Datasheet

System Management Intel® S5000 Server Board Family Datasheet
Revision 1.3
Intel order number D38960-006
130
Boost:
 The associated fan in a critical or non-recoverable state in a non-redundant fan
configuration.
 The fan domain is a state of insufficient resources in a redundant fan configuration.
 Any temperature sensor in a critical or non-recoverable state, with the exception of
Processor Thermal Control Monitoring sensor (Prochot) or VRD Over-Temperature
(VRDHot) sensors.
Sleep:
 No boost conditions, system in ACPI S1 and S3 sleep states, and the BMC is configured
to transition fan domains to sleep state.
Nominal:
 See Section 4.14.1.
4.14.1 Nominal Fan Speed
It is possible to configure a fan domain’s Nominal fan speed to be either static (fixed value) or
controlled by the state of one or more associated temperature sensors.
OEM SDR records are used to configure which temperature sensors are associated with which
fan control domains as well as the relationship (algorithm) between the temperature and fan
speed control (PWM) value. Multiple OEM SDRs may reference / control the same fan control
domain and multiple OEM SDRs may reference the same temperature sensors.
The PWM value for the given domain is computed using one or more instances of a stepwise
linear algorithm and a clamp algorithm. The transition from one computed Nominal fan speed
(PWM value) to a new one is ramped over time to avoid audible transitions. The ramp rate is
configurable via the OEM SDR.
Multiple Additive and Clamp Controls can be defined for each fan domain and used
simultaneously. For each domain, the BMC uses the maximum of all of the domain’s Stepwise
Linear Control contributions and the sum of all of the domain’s Clamp Control contributions to
computes the domain’s total PWM value, with the exception that a stepwise linear instance can
be configured to provide the domain maximum at any time.
Hysteresis may be specified to minimize fan speed oscillation and also to smooth out fan speed
transitions. Its application is described along with the fan contribution methods below. If a
legacy T
CONTROL SDR format does not allow specifying hysteresis, the BMC will assume a
hysteresis value of zero.
4.14.2 Stepwise Linear
4.14.2.1 Fan Speed Contribution
Each Stepwise Linear T
CONTROL sub-record defines a lookup table that maps temperature
sensor readings to fan speeds. The table entries must be in increasing order of temperature.
The BMC walks the table, starting from the end, until it finds a temperature entry that is less