Cell Architecture Explained Version 2

Introduction and Index


Initially designed for the PlayStation 3, Sony, Toshiba and IBM's new Cell processor promises seemingly obscene computing capabilities for what will rapidly become a very low price.

6 months ago I wrote an article describing this new processor based on the original Cell processor patent application from 2002.  Since that original document was written the Cell design evolved considerably in both hardware and software.  The Cell was revealed at ISSCC in February 2005 and since then a great deal of information has been revealed about the final architecture in various articles, papers and interviews.

This new version has been almost completely rewritten to cover the Cell as it is today.  New sections have also been added to cover Cell software development and the reasons behind the choice of a relatively simple architecture.

In part 1 I look at how the Cell came about and it’s main components.  Part 2 looks at the infrastructure components and the concept of stream processing.  Part 3 covers the options for programming the Cell and the issues likely to be encountered.  In Part 4 I look at the design decisions in the Cell and look at why the architecture is so simple compared to other contemporary microprocessors.

Part 1: Inside the Cell

  1.  Background

  1.  So, what is Cell Architecture

  1.  Specifications

  1.  The Power Processor Element (PPE)

  1.  Synergistic Processor Elements (SPEs)

  1.  AltiVec?

  1.  SPE Local Stores

  1.  Local Store V’s Cache

Part 2: Again inside the Cell

  1.  Steam Processing

  1.  The EIB and DMAC

  1.  Memory and I/O

  1.  Memory Management Units

  1.  Processing Concrete

  1.  Hard Real Time Processing

  1.  To DRM or not to DRM?

  1.  Other Options And The Future

Part 3: Programming the Cell

  1.  Developing for the Cell

  1.  Hello Tosh, gotta Toshiba?

  1.  Celling Penguins: Linux on Cell

  1.  Converting Applications for Cell

  1.  Targeting SPEs

  1.  SPE Instruction Set

  1.  Cell Programming Issues

  1.  SPE Performance Issues

  1.  The Future: Multi-Cell'd Animals

  1.  Programming The Cell: Conclusion

Part 4: Revenge of the RISC

  1.  Branching Orders: Is The Cell General Purpose?

  1.  RISC Strikes Back

  1.  Predicting Branches

  1.  Duel Threading

  1.  The Law of Diminishing Returns

  1.  A General Purpose Conclusion

Part 5: Conclusion and References

  1.  Short Overview

  1.  Conclusion

  1.  Acknowledgements

  1.  Further Reading

  1.  References

  1.  Miscellaneous Notes

Introduction and Index

Part 1: Inside The Cell

Part 2: Again Inside The Cell

Part 3: Programming the Cell

Part 4: Revenge of the RISC

Part 5: Conclusion and References

Version 1

The old version can be found here:


© Nicholas Blachford 2005.