NEC Intel Xeon E5-2430 N8101-572F User Manual

Product codes
N8101-572F
Page of 258
Intel® Xeon® Processor E5-1600/E5-2600/E5-4600 Product Families
141
Datasheet Volume One
PROCHOT_N can allow voltage regulator (VR) thermal designs to target maximum 
sustained current instead of maximum current. Systems should still provide proper 
cooling for the VR, and rely on PROCHOT_N as a backup in case of system cooling 
failure. The system thermal design should allow the power delivery circuitry to operate 
within its temperature specification even while the processor is operating at its Thermal 
Design Power. 
With a properly designed and characterized thermal solution, it is anticipated that 
PROCHOT_N will be asserted for very short periods of time when running the most 
power intensive applications. An under-designed thermal solution that is not able to 
prevent excessive assertion of PROCHOT_N in the anticipated ambient environment 
may cause a noticeable performance loss. Refer to the appropriate platform design 
guide and for details on implementing the bi-directional PROCHOT_N feature.
5.2.5
THERMTRIP_N Signal
Regardless of whether Adaptive Thermal Monitor is enabled, in the event of a 
catastrophic cooling failure, the processor will automatically shut down when the silicon 
has reached an elevated temperature (refer to the THERMTRIP_N definition in 
). At this point, the THERMTRIP_N signal will go active 
and stay active. THERMTRIP_N activation is independent of processor activity and does 
not generate any Intel
 
QuickPath Interconnect transactions. If THERMTRIP_N is 
asserted, all processor supplies (VCC, VTTA, VTTD, VSA, VCCPLL, VCCD) must be 
removed within the timeframe provided. The temperature at which THERMTRIP_N 
asserts is not user configurable and is not software visible.
5.2.6
Integrated Memory Controller (IMC) Thermal Features
5.2.6.1
DRAM Throttling Options
The Integrated Memory Controller (IMC) has two, independent mechanisms that cause 
system memory throttling:
• Open Loop Thermal Throttling (OLTT) and Hybrid OLTT (OLTT_Hybrid)
• Closed Loop Thermal Throttling (CLTT) and Hybrid CLTT (CLTT_Hybrid)
5.2.6.1.1
Open Loop Thermal Throttling (OLTT)
Pure energy based estimation for systems with no BMC or Intel ME. No memory 
temperature information is provided by the platform or DIMMs. The CPU is informed of 
the ambient temperature estimate by the BIOS or by a device via the PECI interface. 
DIMM temperature estimates and bandwidth control are monitored and managed by 
the PCU on a per rank basis.
5.2.6.1.2
Hybrid Open Loop Thermal Throttling (OLTT_Hybrid)
Temperature information is provided by the platform (for example, BMC or Intel® 
Management Engine (Intel® ME)) through PECI and the PCU interpolates gaps with 
energy based estimations.
5.2.6.1.3
Closed Loop Thermal Throttling (CLTT)
The processor periodically samples temperatures from the DIMM TSoD devices over a 
programmable interval. The PCU determines the hottest DIMM rank from TSoD data 
and informs the integrated memory controller for use in bandwidth throttling decisions.