Specifications Platform OS CPU #Cores MacBook Air OS X 10.9.2 - - PowerPoint PPT Presentation

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Mar 10, 2024 11 likes •61 views

Specifications Platform OS CPU #Cores MacBook Air OS X 10.9.2 1.7 GHz Intel Core i7 2 Linux Desktop Ubuntu 13.10 3.4 GHz Intel Core i7 4 Titan Cray Linux 16 2.2GHz AMD Opteron 6274 (Interlagos) Supada (ORNL) Geant4 Multithreading

SLIDE 1

Specifications

Platform OS CPU #Cores MacBook Air OS X 10.9.2 1.7 GHz Intel Core i7 2 Linux Desktop Ubuntu 13.10 3.4 GHz Intel Core i7 4 Titan Cray Linux

2.2GHz AMD Opteron 6274

16 (Interlagos)

Supada (ORNL) Geant4 Multithreading April 16, 2014 1 / 5

SLIDE 2

Case Study Basic Geant4 example B2a 10,000 events

Supada (ORNL) Geant4 Multithreading April 16, 2014 2 / 5

SLIDE 3

Execution Time

1 2 4 8 16 20 40 60 80 100 120 Number of Threads Execution Time (seconds)

MacBook Air Linux Desktop Titan

Supada (ORNL) Geant4 Multithreading April 16, 2014 3 / 5

SLIDE 4

Speedup in Theory Sp = T1 Tp

T1 = execution time on one thread Tp = execution time on p threads Ideally: Tp = T1 p = ⇒ Sp = p Reality: Tp = T1 p + Tc = ⇒ Sp < p, where Tc is the communcation time among threads

Supada (ORNL) Geant4 Multithreading April 16, 2014 4 / 5

SLIDE 5

Speedup

1 2 4 8 16 2 4 6 Number of Threads Speedup

MacBook Air Linux Desktop Titan

Supada (ORNL) Geant4 Multithreading April 16, 2014 5 / 5