NOCS-2009Chita R. Das

National Science Foundation/Pennsylvania State University

Domain

Q. NoCs in MPSoC vs. NoCs in CMPs - Are they really different?

- At a functional level NOT, but- Typically CMPs are homogenous and SoC’s are

heterogeneous- However, with heterogeneous CMPs, many

design issues will be common- Future CPU’s would have accelerators, GPU’s,

memory (through 3D stacking), etc making them not much different from SoC’s

Image Source: IBM Cell and Internet

Workloads

Q. Aren't we may be over-hype the importance of NoCs?

- Probably YES unless we understand the workload dynamics and show how it can stress the network

- Current workloads have low injection rates- Multimedia application (gaming and video) and

emerging workloads ( RMS, PARSEC) may stress on-chip networks

- Data-Center On Chip- If bandwidth is not stressed then can we

virtualize CMP?

Image Source: Internet

Programming model

Q. NoC universal replacement?

- Good to be imaginative!!!- NoC is a substrate for the CMPs/SoCs. It will be

great if it influences the programming model- Programming model for multi-cores is a

challenge - Compilers/OS may be interconnect aware to

enable run-time optimizations - Miracles occur!

Image Source: Internet

Next big thing

Q. What are the most urgent research issues we should address?

- Workload characterization- Power-aware NoCs.- Scalable, adaptable, intelligent, and reusable NoCs for large systems- Adapting emerging technologies like RF, Optical interconnect, 3D, CNT, etc - Application Specific NoC Design- Performance Isolation, QoS, and Fairness- Fault-tolerance- Performance, power, Reliability trade-offs- Understanding the architectural and technology trade-offs

Image Source: IBM and Internet

Scope and impact

Q. What kind of results should sponsors (e.g., NSF, GRC, companies) expect over the next 5-10 years?

“Science” of designing on-chip networks for next generations CMPs/SoCs

Original image: http://www.macvspc.info/pages/13.html