Fresh Breeze: A Programmable Multicore System Architecture

Computation Structures Group, CSAIL
Jack B. Dennis, Professor Emeritus

Computer architects have found that putting several processor cores on the same chip is a better way of using silicon area than attempting to achieve greater performance by adding further complexity to a single processor. Moreover, the increased performance is obtained for significantly less energy consumption. However, the result so far is chips that are very difficult to program to realize their performance potential.

The Fresh Breeze Project is attacking this programmability problem using concepts from functional programming, principles of modular software construction, and global shared address spaces. Our approach is to incorporate several ideas that are significant departures from conventional thinking about multicore system architecture:
By implementing a shared global address space, the cost of implementing fine-grain cooperation of multiple processors can be greatly reduced. Also, the conventional distinction between "memory" and the file system can be abolished, simplifying programming, as has been demonstrated in Multics. A more radical departure from convention is the implementation of a cycle-free heap of information "chunks" that are created, used, and released, but never modified once created. Memory management is performed done by efficient hardware mechanisms.

More information may be found at

Topics suitable for Master of Engineering Projects include: performance analysis of specific applications on a Fresh Breeze system; memory management studies; design of an external shared memory system for a system built of Fresh Breeze chips; failure recovery in a Fresh Breeze system; implementation of load balancing; transaction processing applications.

For more information, contact Prof. Jack Dennis ( ).