Outline Parallel computing with GPU NVIDIA CUDA Conclusion

Outline • Parallel computing with GPU • NVIDIA CUDA • Conclusion 11/17/09 ICAL 2

Parallel computing with GPU • • • Parallel computing Flynn’s Taxonomy Algorithm decomposed Amdahl’s Law Correctness concepts 11/17/09 ICAL 3

Parallel computing • Parallel computing is a form of computation in which many calculations are carried out simultaneously. • Parallel computers hardware: – – 11/17/09 Single machine: multi-core CPU, GPU Multiple machines: clusters, MPPs, grid ICAL 4

Parallel computing (cont. ) • There are several kinds of parallel computing, such as: – Bit-level – Instruction level – Data decomposed – Task decomposed • The parallel computing has the speedup limit. 11/17/09 ICAL 5

Algorithm decomposed • Task decomposition • Data Decomposition Prepared the Dinner Cleaning table Wishing dishes Purchasing Cooking Enjoy the dinner John clean the table 11/17/09 Mary go shopping ICAL John and Mary wishing dishes 6

Flynn’s Taxonomy Instruction Multiple Single Data 11/17/09 Single Multiple SISD SIMD MISD MIMD ICAL 7

Amdahl’s Law • Amdahl's law is a model for the expected speedup from partial improvement P: Parallel Portion S: Speedup of parallel portion 11/17/09 ICAL 8

Correctness concepts • Race condition • Deadlock Read a …… a=19 …… save a=21 save a=a+1 …… a=20 …… ERROR! 11/17/09 ICAL 9

NVIDIA CUDA • • Historical Trends CUDA Programming Languages Reported Speedup 11/17/09 ICAL 10

Historical Trends 11/17/09 ICAL 11

CUDA • Compute Unified Device Architecture, CUDA • CUDA is a computing engine in NVIDIA GPU (graphics processing units) 11/17/09 ICAL 12

Programming Languages Application C/C++ Fortran Open. CL . . . NVIDIA GPU with the CUDA Parallel Computing Architecture 11/17/09 ICAL 13

Reported Speedup 11/17/09 ICAL 14

CUDA Architecture • • • Physical Reality behind CUDA Architectures Introducing the “Fermi” Architecture SM Architecture CUDA Core Architecture 11/17/09 ICAL 15

Physical Reality behind CUDA CPU (host) GPU (device) Main Memory 11/17/09 ICAL 16

CUDA Architectures • G 80 – First CUDA-capable processor • G 8 x, G 9 x – Global memory • GT 200 – – 11/17/09 Double precision Shared memory Larger register file Relaxed memory coalescing rules Basic CUDA architecture ICAL 17

“Fermi” Architecture 11/17/09 • 3 billion transistors • Over 2 x the cores (512 total) • 8 x the peak DP performance • L 1 and L 2 caches • ~2 x memory bandwidth • Up to 1 terabyte of GPU memory ICAL 18

SM Architecture 11/17/09 • 32 CUDA cores per SM (Streaming Multiprocessor) • 8 x peak double precision floating point performance • Dual Thread Scheduler • 64 KB of RAM for shared memory and L 1 cache ICAL 19

CUDA Core Architecture 11/17/09 • New IEEE 754 -2008 floating-point standard • Fused multiply-add (FMA) instruction for both single and double precision • Newly designed integer ALC optimized for 64 -bit and extended precision operations ICAL 20

Conclusion • Using GPU to improve the program speed is feasible, it can speedup performance of the cloud computing. • NVIDIA CUDA is good with SIMD parallel computing. • But there additional costs about Data passing between main memory and GPU memory. 11/17/09 ICAL 21