Evaluating an Adaptive Framework For Energy Management in Processor- In-Memory Chips Michael Huang, Jose Renau, Seung-Moon Yoo, Josep Torrellas

ICAP'00 9/13/002 Motivations  Power consumption –Cooling –Battery  Architectural framework –Circuit optimizations –Dynamic techniques

ICAP'00 9/13/003 Goals  Enforcing temperature/power limit –Eliminate/reduce cooling requirements  Maximizing energy saving while exploiting performance slack –Offers high performance or energy-efficiency

ICAP'00 9/13/004 Static Design Optimizations  Cache parameters –size, block size, associativity...  DRAM organizations, parameters –interleaving, subbanking, pipelining….  Buffers, blah…. Paper in our web site.

ICAP'00 9/13/005 FlexRAM -- the baseline architecture Simple processors Concurrency - peaks

ICAP'00 9/13/006 Simulation Environment  MHz 2- issue processors  8K 1- cycle D-Cache, 1 MB 12- cycle DRAM  8K I-Mem (SRAM, shared), 256B filter cache  Energy numbers: –Cache hit: 222.8pJ, –Row buffer access: 469pJ, –DRAM cell access: 2250pJ, –I-Mem access: 103.2pJ, –Filter cache hit: 26.5pJ, –Subbanking cache hit: 64.8pJ, –Base instruction: 34.8pJ pJ … …

ICAP'00 9/13/007 Dynamic Techniques Filter cache Voltage Scaling Cache Sub-banking Slow Hit Sleep Comb & Grad  Filter Cache

ICAP'00 9/13/008 Evaluation - Energy Delay

ICAP'00 9/13/009 Evaluation - Delay

ICAP'00 9/13/0010 Evaluation - Energy

ICAP'00 9/13/0011 Evaluation - Power Limit

ICAP'00 9/13/0012 Algorithm

ICAP'00 9/13/0013 Algorithm (cont)

ICAP'00 9/13/0014 Slack - Energy Consumption

ICAP'00 9/13/0015 Slack - Execution Time

ICAP'00 9/13/0016 Conclusions  Effectively limits power consumption –very few microcycles still over limit  Efficient exploitation of slack –10% slack offers 40% energy saving

ICAP'00 9/13/0017 Work in Progress  Adaptively reorder techniques –Profiling based, –Compiler directed, –Runtime monitoring.

Evaluating an Adaptive Framework For Energy Management in Processor- In-Memory Chips Michael Huang, Jose Renau, Seung-Moon Yoo, Josep Torrellas To appear in 33rd Int’l Symp of Micro, Dec 2000, California