TemperatureAware Design温度感知的设计.ppt

Training course design
TemperatureAware Design温度感知的设计
1
The Problem
Power & Thermal densities are increasing
Currently 50W/cm2, 100W/cm2 50nm technology
Power density doubles every 3 years
Operating Vdd scaling much more slowly (ITRS)
Cost of cooling rising exponentially
$1 - $3 per Watt of power dissipation
Packages designed for worst case power
Hot spots – heat dissipation non-uniform across chip
Low-Power design techniques not sufficient
Big Hammer : Global Clock Gating limits performance
Impact of Temperature on Design
Increased Delay, Lower Reliability
Slower Transistors
Carrier mobility lower at higher temperature
Inverter 35% slower at 110o C vs. 60o C
Higher Leakage Power
By orders of magnitude at higher temperature
Leakage becoming more significant than switching power
Higher Metal Resistivity
Copper 39% more resistive at 120o C vs. 20o C
Lower Mean-Time-To-Failure (MTF)
MTF = MTFo exp (Ea / kb T)
MTF decreases exponentially w/ Temperature
Moral of the Story
Problem: Temperature adversely affects power, performance & reliability
Solution: “Temperature-Aware” Design
Temperature Aware Design
Thermal Modeling
Estimate Operating Temperature
Simple : Allow architects to easily reason about thermal effects
Detailed : Model runtime temperature at Functional-Unit granularity
Computationally Efficient
Flexible : Easily extend to novel architectures
Dynamic Thermal Management
Use runtime behavior and thermal status to adjust/distribute workload among Functional-Units
Talk Outline
Thermal Modeling
Model Description
Validation & Case Studies
Dynamic Thermal Management
Results
Conclusions
References
Kevin Skadron et. al, “Temperature-Aware Microarchitecture”
Wei Huang et. al, Compact Thermal Modeling for Temperature-Aware Design”
Thermal Modeling
Thermal model interacts with Power, Performance, Reliability models
Design convergence requires several iterations
Heat Flow vs. Electrical Phenomenon
Both can