SAID Issam

PhD student at Sorbonne University
Team : PEQUAN
https://perso.lip6.fr/Issam.Said

Supervision : Jean-Luc LAMOTTE
Co-supervision : FORTIN Pierre

Contributions of hybrid architectures to depth imaging: a CPU, APU and GPU comparative study

In an exploration context, Oil and Gas (O&G) companies rely on HPC to accelerate depth imaging algorithms.

Solutions based on CPU clusters and hardware accelerators are widely embraced by the industry. The Graphics Processing Units (GPUs), with a huge compute power and a high memory bandwidth, had attracted significant interest.

However, deploying heavy imaging workflows, the Reverse Time Migration (RTM) being the most famous, on such hardware had suffered from few limitations.

Namely, the lack of memory capacity, frequent CPU-GPU communications that may be bottlenecked by the PCI transfer rate, and high power consumptions. Recently, AMD has launched the Accelerated Processing Unit (APU): a processor that merges a CPU and a GPU on the same die, with promising features notably a unified CPU-GPU memory.

Throughout this thesis, we explore how efficiently may the APU technology be applicable in an O&G context, and study if it can overcome the limitations that characterize the CPU and GPU based solutions. The APU is evaluated with the help of memory, applicative and power efficiency OpenCL benchmarks.

The feasibility of the hybrid utilization of the APUs is surveyed. The efficiency of a directive based approach is also investigated. By means of a thorough review of a selection of seismic applications (modeling and RTM) on the node level and on the large scale level, a comparative study between the CPU, the APU and the GPU is conducted. We show the relevance of overlapping I/O and MPI communications with computations for the APU and GPU clusters, that APUs deliver performances that range between those of CPUs and those of GPUs, and that the APU can be as power efficient as the GPU.


Phd defence : 12/21/2015

Jury members :

M. François Bodin, Professeur, Université de Rennes 1 [Rapporteur]
M. Christophe Calvin, Chef de projet, CEA [Rapporteur]
M. Henri Calandra, Expert en imagerie profondeur et calcul haute performance, Total
M. Pierre Fortin, Maître de conférences, Université Pierre et Marie Curie
M. Lionel Lacassagne Professeur, Université Pierre et Marie Curie
M. Jean-Luc Lamotte Professeur, Université Pierre et Marie Curie
M. Mike Mantor, Corporate Fellow, AMD
M. Stéphane Vialle, Professeur, SUPELEC campus de Metz

Departure date : 12/31/2015

2012-2018 Publications