1. SOS7 -- Crystal Ball or a random walk through Mike's brain Mike Merrill March 6, 2003

2. Architecture Matters This is kind of dated but still relevant… Now we just put them into racks… And they might not be this bad… but they might…

3. Questions What future holds for supercomputing? more of the same unless we can buy or do something different not so bad for most but we’ll never solve our toughest problems What do we want to see? balance, ease, utility, etc... This is a license to say just about anything ;-)

4. What makes a supercomputer? It’s really all about application performance Large Scale Balance Mission Utility Balance of Effort vs. Cost Ease of Use Bandwidth

5. Compute Efficiency vs. Human Efficiency Ease of use usable memory bandwidth avoid/hide/manage latency the right compiler and OS support user’s will do what is easy unless they are like me something is always getting used at 100% whose time is more important? a person can only write so much code before death

6. Programming Abstraction Ditch the explicit communication Ditch the explicit threading/processes in the “language” Allow for higher level abstractions Make the non-performance critical part (90%) of the code easier to develop Allow for more optimizations We will never get some of our best scientists to do some optimizations

7. Data Structures are Important The other 90% of what you learned from the “Art of Computer Programming” Sparse Methods are very important Most useful real world data structures have some linked or random nature to them Future architectures should support these in a more meaningful way than current and near- term architectures do. Also need scalable address translation unlike vectors TLBs suck worse

8. Message Passing vs. Shared Memory this is not the issue the issue is overhead I happen to like the look and feel of a global address space My LOC is much less using UPC or CAF still don’t like fixed number of threads/contexts

9. Leverage Advances in HW Technology Not just more of the same ($) Use die area in a more effective way supporting programming abstraction i.e. support for virtualization of resources More effective interconnection lower overhead use die area for more effective protocols

10. Gross View of Resources Past Recent Past Now and Near Term Capacity and Capability CapacityCapability WS FarmHigh Capacity Server Large Scale Capability

11. Conclusions I am still optimistic about the future When I’ve stopped complaining... then I’ll go fishing “Ease of use is a myth if you want more power” “Parallel memory access is the cornerstone of a computing civilization”