17 citations · 58 across the 14 of their papers we have counts for
16 papers
Exploiting the Interplay of Compute- and Memory-Bound kernels in MPI Applications
Ayesha Afzal, Krishna Manda, Georg Hager
Parallel applications are often designed for synchronous, lock-step execution, treating communication stalls as performance hazards. Yet, in a communication-light application witho…
Modeling and Chasing the Energy-Efficiency Sweet Spots in Modern GPUs
Ayesha Afzal, Markus Manfred Li, Michael Panzlaff
Energy consumption is a key limitation in high-performance computing on heterogeneous CPU-GPU systems. This work studies how hardware configuration affects energy-to-solution under…
The Illusion of Power Capping in LLM Decode: A Phase-Aware Energy Characterisation Across Attention Architectures
Bole Ma, Ayesha Afzal, Jan Eitzinger +1
Power capping is the standard GPU energy lever in LLM serving, and it appears to work: throughput drops, power readings fall, and energy budgets are met. We show the appearance is…
Wattlytics: A Web Platform for Co-Optimizing Performance, Energy, and TCO in HPC Clusters
Ayesha Afzal, Georg Hager, Gerhard Wellein
The escalating computational demands and energy footprint of GPU-accelerated computing systems complicate informed design and operational decisions. We present the first release of…
GROMACS Unplugged: How Power Capping and Frequency Shapes Performance on GPUs
Ayesha Afzal, Anna Kahler, Georg Hager +1
Molecular dynamics simulations are essential tools in computational biophysics, but their performance depend heavily on hardware choices and configuration. In this work, we present…
Exploring metrics for analyzing dynamic behavior in MPI programs via a coupled-oscillator model
Ayesha Afzal, Georg Hager, Gerhard Wellen
We propose a novel, lightweight, and physically inspired approach to modeling the dynamics of parallel distributed-memory programs. Inspired by the Kuramoto model, we represent MPI…
Analytic Roofline Modeling and Energy Analysis of LULESH Proxy Application on Multi-Core Clusters
Ayesha Afzal, Georg Hager, Gerhard Wellein
We present a thorough performance and energy consumption analysis of the LULESH proxy application in its OpenMP and MPI variants on two different clusters based on Intel Ice Lake (…
Physical Oscillator Model for Supercomputing
Ayesha Afzal, Georg Hager, Gerhard Wellein
A parallel program together with the parallel hardware it is running on is not only a vehicle to solve numerical problems, it is also a complex system with interesting dynamical be…
SPEChpc 2021 Benchmarks on Ice Lake and Sapphire Rapids Infiniband Clusters: A Performance and Energy Case Study
Ayesha Afzal, Georg Hager, Gerhard Wellein
In this work, fundamental performance, power, and energy characteristics of the full SPEChpc 2021 benchmark suite are assessed on two different clusters based on Intel Ice Lake and…
Making Applications Faster by Asynchronous Execution: Slowing Down Processes or Relaxing MPI Collectives
Ayesha Afzal, Georg Hager, Stefano Markidis +1
Comprehending the performance bottlenecks at the core of the intricate hardware-software interactions exhibited by highly parallel programs on HPC clusters is crucial. This paper s…
Exploring Techniques for the Analysis of Spontaneous Asynchronicity in MPI-Parallel Applications
Ayesha Afzal, Georg Hager, Gerhard Wellein +1
This paper studies the utility of using data analytics and machine learning techniques for identifying, classifying, and characterizing the dynamics of large-scale parallel (MPI) p…
The Role of Idle Waves, Desynchronization, and Bottleneck Evasion in the Performance of Parallel Programs
Ayesha Afzal, Georg Hager, Gerhard Wellein
The performance of highly parallel applications on distributed-memory systems is influenced by many factors. Analytic performance modeling techniques aim to provide insight into pe…
Analytic Modeling of Idle Waves in Parallel Programs: Communication, Cluster Topology, and Noise Impact
Ayesha Afzal, Georg Hager, Gerhard Wellein
Most distributed-memory bulk-synchronous parallel programs in HPC assume that compute resources are available continuously and homogeneously across the allocated set of compute nod…
An analytic performance model for overlapping execution of memory-bound loop kernels on multicore CPUs
Ayesha Afzal, Georg Hager, Gerhard Wellein
Complex applications running on multicore processors show a rich performance phenomenology. The growing number of cores per ccNUMA domain complicates performance analysis of memory…
Desynchronization and Wave Pattern Formation in MPI-Parallel and Hybrid Memory-Bound Programs
Ayesha Afzal, Georg Hager, Gerhard Wellein
Analytic, first-principles performance modeling of distributed-memory parallel codes is notoriously imprecise. Even for applications with extremely regular and homogeneous compute-…
Propagation and Decay of Injected One-Off Delays on Clusters: A Case Study
Ayesha Afzal, Georg Hager, Gerhard Wellein
Analytic, first-principles performance modeling of distributed-memory applications is difficult due to a wide spectrum of random disturbances caused by the application and the syst…