System Power Management Power Architecture and Power Monitoring. Ken Boyden International Rectifier September, 2006

Transcription

1 System Power Management Power Architecture and Power Monitoring Ken Boyden International Rectifier September, 2006

2 Heat Densities Future trend

3 Problem Management of cooling simply by monitoring temperature has several problems Thermal Latency Thermal response lag time is usually long compared to the stimulating events Reduction of cooling usually comes too early No knowledge of what is coming next Typical hysteretic mode or linear mode fan control has several issues Cooling response is triggered by thermostatic trigger events rather than actual power requirements Or by linear thermal response where the cooling lags the thermal rise This causes excessive response by the fan cooling system Efficiency is dynamic not just static Thermal spikes are caused by power loss spikes If we could react to power rather than thermal events we could reduce loss peaks by controlling thermal-resistive elements in the system

4 Power Distribution in a Data Center Data Center efficiency = Power Delivered to IT Equipment Total input Power Typical Data Center Efficiency 30% to 60% Source: Electrical Efficiency Modeling for Data Centers

5 Annual Utility Cost for just the Server Taken from an independent study of server cost of ownership for industry standard severs All servers were chosen to provide nearly equal performance 120K opps /sec.

6 Server Annual Cost of Operation Total Consumption Cooling Fans Annual Cost of Power VR Annual Cost of Power Savings Server Package KW Electrical AC Watts AC Cost 75% eff. BLDC 85% eff. VR now 87% eff. VR future 92% eff. Electrical AC Total p650/linux 1.60 $1, $420 $171 $151 $535 $478 $76 $28 $105 DL740/Linux 1.60 $1, $420 $171 $151 $535 $478 $76 $28 $105 DL740/Windows 1.60 $1, $420 $171 $151 $535 $478 $76 $28 $105 rx5670/linux 2.79 $1, $732 $297 $262 $932 $834 $133 $49 $182 rx5670/windows 2.79 $1, $732 $297 $262 $932 $834 $133 $49 $182 SunFire/Solaris 3.92 $2, $1,029 $418 $369 $1,310 $1,172 $187 $69 $256 Cluster/Linux 1.85 $1, $486 $197 $174 $618 $553 $88 $33 $121 Cluster/Windows 1.85 $1, $486 $197 $174 $618 $553 $88 $33 $121

7 Other Cost Factors Reliability Transistor MTBF is exponential function of operating junction temperature A junction temperature rise of as little as 10 C can halve the lifetime of the component Performance Noise The microprocessor can operate at higher clock speeds with lower junction temperatures. Gate delays are also reduced. Power due to leakage current is also reduced at lower temperatures. Using PMAC motors with sinusoidal drive and tightly controlled power, significantly reduces both acoustic and EM noise.

8 Dynamic Thermal Management Most Package and cooling designs are based upon peak thermal events It takes over 5 ms to retrieve processor temperature data via Serial Management Buses Dynamic thermal management allows us to design for lower thermal events Dynamic voltage positioning already provides about a 10% savings in overall thermal budget. Sensing instantaneous and average power provides extra trigger points other than just extreme thermal events By monitoring both power and temperature it is possible to dynamically profile the processing environment. Statistical analysis can be used to determine trigger points for cooling based upon power and temperature sensing. Thermal reduction Mechanisms: FAN Clock reduction Voltage Scaling Cache/Core enabling

9 Thermal Throttling Intel Pentium Performance throttling(clock/voltage) is currently used to control thermal envelope. The big issue with this is the long thermal response time which causes thermal overshoot Throttling of VIDs also causes efficiency losses Source-Intel Technology Journal

10 Actual Thermal Envelope Throttling Area

11 Envelope controlled with Dynamic Power Management

12 Design for Power vs. Performance Source-Intel Technology Journal

13 VR Efficiency Efficiency Current Amps Thermal Max. Design Point

14 VR Efficiency Efficiency Dynamic Power Controlled Design Point Current Amps

15 Fan Efficiency Thermal Max. Design Point

16 Fan Efficiency Dynamic Power Controlled Design Point

17 Initial Server Costs Total Consumption Cooling Server Package KW Electrical AC Watts AC Cost p650/linux 1.60 $1, $420 DL740/Linux 1.60 $1, $420 DL740/Windows 1.60 $1, $420 rx5670/linux 2.79 $1, $732 rx5670/windows 2.79 $1, $732 SunFire/Solaris 3.92 $2, $1,029 Cluster/Linux 1.85 $1, $486 Cluster/Windows 1.85 $1, $486

18 Costs with 20% reduction in Cooling Power Consumption Total Consumption Cooling Electrical AC Server Package KW Electrical AC Watts AC Cost Server Package Savings Savings Total p650/linux 1.60 $1, $336 p650/linux $114 $84 $198 DL740/Linux 1.60 $1, $336 DL740/Linux $114 $84 $198 DL740/Windows 1.60 $1, $336 DL740/Windows $114 $84 $198 rx5670/linux 2.79 $1, $586 rx5670/linux $198 $146 $345 rx5670/windows 2.79 $1, $586 rx5670/windows $198 $146 $345 SunFire/Solaris 3.92 $2, $823 SunFire/Solaris $278 $206 $484 Cluster/Linux 1.85 $1, $388 Cluster/Linux $131 $97 $228 Cluster/Windows 1.85 $1, $388 Cluster/Windows $131 $97 $228 10% Electrical savings assumed by controlling the loadpoint for the entire power train 20% savings assumed by reducing the AC requirements

19 Costs with 30% reduction in Cooling Power Consumption Total Consumption Cooling Electrical AC Server Package KW Electrical AC Watts AC Cost Server Package Savings Savings Total p650/linux 1.60 $1, $336 p650/linux $114 $130 $243 DL740/Linux 1.60 $1, $336 DL740/Linux $114 $130 $243 DL740/Windows 1.60 $1, $336 DL740/Windows $114 $130 $243 rx5670/linux 2.79 $1, $586 rx5670/linux $198 $226 $424 rx5670/windows 2.79 $1, $586 rx5670/windows $198 $226 $424 SunFire/Solaris 3.92 $2, $823 SunFire/Solaris $278 $318 $596 Cluster/Linux 1.85 $1, $388 Cluster/Linux $131 $150 $281 Cluster/Windows 1.85 $1, $388 Cluster/Windows $131 $150 $281 10% Electrical savings assumed by controlling the loadpoint for the entire power train 30% savings assumed by reducing the AC requirements

20 Data Center Example In a Data Center example, we see the greatest savings from Dynamic power control and designing for the actual power envelope Source: Electrical Efficiency Modeling for Data Centers

21 Requirements for Solution Board based Power Management Control Control loop based upon Load Power rather than thermal events Accurate monitoring of each system Load point This includes FBDIMM VR Chipset Drive Modules Graphics control System Based Power Control Consolidates inputs from board/ module power controllers Control enclosure fans Provide system loading commands Control VRs

22 Intelligent Platform Fan Control VR PM Chipset Power Info System management Controller Control FBDIMM VR PM VR PM VR PM VR PM FBDIMM

23 Controlling the Data Center - IPMI Blade or MP board Internet Source-Intel

24 Future Developments Processor Integrated Power Detection elements Energy per Operation detection Instruction Cache toggling Clock gating VR Intimate tie between CPU and VR voltage Operating system Speculative Processing Like speculative branching but set up to minimize peak power events

25 Summary and Feedback The Majority of Data Center and Server Costs come from controlling the operating environment Most of the innovation has gone into the power train A method of determining and communicating actual dynamic power is needed Next Steps

26 Bibliography Dynamic Thermal Management for High-Performance Microprocessors David Brooks, Margaret Martonosi Dynamic Thermal Management for Distributed Systems Andreas Weissel, Frank Bellosa Electrical Efficiency Modeling for Datacenters Neil Rasmussen Intelligent Power Management Interface Specification Increasing Data Center Density While Driving Down Power and Cooling Costs Intel Corporation Energy Efficient Server Clusters E.N. Elnozahy, Michael Kistler, Ramakrishnan Rajamony SharkRack: The Problem of Thermal Management HP corporation Thermal Performance Challenges from Silicon to Systems Ram Viswanath, Vijay Wakharkar, Abhay Watwe, Vassou Lebonheur, Intel Corp. Total Cost of Ownership for Enterprise Application Workloads Robert Frances Group

27 A New Thermal Management Concept CPU and System Thermal Inputs Server Management Module PMBus or I2C 8051 ucontroller Blower Controller #1 VRMs & POLs To PFC FET gate Power Feedback and load control via PMBus or I2C PFC IR Variable Speed Blower Controller Blower Controller #2

28 Server Thermal Management: A Different Approach A dual Motor/Blower controller utilizing Sensor-less control to Remove costly Hall Effect Sensors Remove PSOC times (n) blowers Remove Housekeeping supplies for PSOC in each Blower Improve Machine performance and efficiency An improved PFC That increases overall conversion efficiency thus reducing Blower Power Dissipation, Data Center TCO and / or increases CPU utilization Removes costly redundancy of PFC in each blower Improved overall Blower System Efficiency Using Proprietary IR technology in PFC, Bridge and VS controls Increase CPU Utilization, or reduction in power, cooling requirements and TCO Increased blower control functionality Improve granularity of blower control Further Reduce Noise Remove System Latency, which improves efficiency

29 Total Platform Power Control: A VISION Imagine Knowing the power draw of each power subsystem Imagine Being Able to Make Real Time Decisions to Optimize Performance While Maintaining a Thermal Envelope Imagine Knowing which subsystem to throttle to maximize User demanded performance Imagine Knowing the system is running its coolest and quietest IR Subsystem Power Monitoring

30 IR3720 Discrete Power Monitor And Temperature Sensor Flexible Current Sensing DCR or Resistor VCC Block Diagram ALARM# Single Output or Multiphase Remote Temperature Sense Uses External NTC Programmable Alarm Alerts microcontroller of excessive average power, or Over Temperature IOUT ISEN SENREF VSEN RTN X + - R F DCR Io ( VO RTN) R I VCO Clock N N Counter R STROBE > PWR Register 9 ALARM Register SMBus Slave ADD1 ADD2 SDA SCL Set N T AVG Register GND

31 XPhase Generation 3 Gen 3 Enhancements 25% Higher Switching frequency with same power loss Reduced output capacitors Reduced external components Reduced system cost Improved accuracy 25% improvement in power density Easier to use