Alternative ProcessorsHPC User Forum Panel1 HPC User Forum Alternative Processor Panel Results 2008

Alternative ProcessorsHPC User Forum Panel2 Alternative Processors Mainstream Processors –Multi-Core Direction –Single Thread Speeds At Best Remain Constant Most Probably Be Reduced –Improve Throughput –No Improvement for Time-to-Solution Application Re-Write Requirements

Alternative ProcessorsHPC User Forum Panel3 Alternative Processors Tough Scientific and Engineering Problems –Not all Can Utilize Parallel Processing –Require Raw Compute Speed Improvement –Will not Get this from Future Mainstream Processors

Alternative ProcessorsHPC User Forum Panel4 Alternative Processors Alternatives: –FPGAs –GPUs Possible Performance Improvement Utilized via Hybrid Configuration Programmability Issues –Some Also Apply to Mainstream Multi-Core Processors

Alternative ProcessorsHPC User Forum Panel5 Alternative Processors FPGAs –Native Environment is Analog Computing Star Bridge Viva is an example –Complicated and Esoteric –Some Success with Significant Programming Investment

Alternative ProcessorsHPC User Forum Panel6 Alternative Processors GPUs –Limited; Designed for Visualization Optimized for Games –Some Vector Capability Integer Low Precision Floating-Point –Cell Processor New Addition of High Precision Floating-Point

Alternative ProcessorsHPC User Forum Panel7 Alternative Processors Hybrid Configurations –Multiple Processor Types in a Somewhat Integrated Environment –Can Provide an Evolutionary Path when a Mainstream Processor is included –Additional Complexity Introduced

Alternative ProcessorsHPC User Forum Panel8 Alternative Processors Programming Environment –Already too Complex Application Parallelization Awkward –MPI is the most Prevalent Mechanism –Multi-Core increases this Complexity –Hybrid Configurations add Complexity –Need Abstraction Support Compilers Run Time

Alternative ProcessorsHPC User Forum Panel9 Alternative Processors Abstraction –Return of Vectors is encouraging Well understood by the HPC community Good Fortran Vector support in classical Cray Compiler –Hardware Addressing Support for Global Memory –Necessary for making these new machines manageable

Alternative ProcessorsHPC User Forum Panel10 Alternative Processors Conclusion –Potential for Significant Contribution to HPC –Requires a Simplification of the Programming Environment Compensate for Increased Complexity while delivering underlying Hardware Capability Support Legacy Code Provide for a Smooth Evolution