arXiv subjects

Timon Evenblij

Publications and source records attributed to Timon Evenblij.

3 recordsLinked to original sources

arXiv2026

Characterizing Machine Learning Force Fields as Emerging Molecular Dynamics Workloads on Graphics Processing Units

Molecular dynamics (MD) simulates the time evolution of atomic systems governed by interatomic forces, and the fidelity of these simulations depends critically on the underlying force model. Classical force fields (CFFs) rely on fixed functional forms fitted to experimental or theoretical data, offering computational efficiency and broad applicability but limited accuracy in chemically diverse or reactive environments. In contrast, machine learning force fields (MLFFs) deliver near quantum chemical accuracy at molecular-mechanics cost by learning interatomic interactions directly from high level electronic structure data. While MLFFs offer improved accuracy at a fraction of the cost of quantum methods, they introduce significant computational overhead, particularly in descriptor evaluation and neural network inference. These operations pose challenges for parallel hardware due to irregular memory access, minimum data reuse and inefficient kernel execution. This work investigates the hardware performance of such models using poly alanine chains, a novel benchmark molecule system(s) with controllable input size, which used as performance evaluation test cases highlighting the computational bottlenecks of the graphical processor units when scaling out MLFF simulations. The analysis identifies key bottlenecks in descriptor and force computation, memory handling, highlighting the opportunities for improvements in the emerging area of MLFF based MD in drug discovery, that has received limited attention from a computer architecture perspective.

cs.PF↗

arXiv2025

System-performance and cost modeling of Large Language Model training and inference

Large language models (LLMs), based on transformer architectures, have revolutionized numerous domains within artificial intelligence, science, and engineering due to their exceptional scalability and adaptability. However, the exponential growth in LLM size and complexity has outpaced advancements in compute capacity, memory bandwidth, network performance, and cost efficiency, posing significant challenges to their scalability on distributed systems. To address these limitations, alternative model architectures, optimization strategies, communication-aware network topologies, and novel system design approaches have been proposed in literature. This paper introduces a performance-cost modeling methodology for LLM training and inference that integrates state-of-the-art compute techniques with memory optimizations, and latest communication techniques. Building on an analytical performance model, our approach incorporates recent innovations such as the flash attention technique and mixture of experts models to address the memory bandwidth and compute bottlenecks. It also considers the impact of different network topologies and topology-specific communication algorithms with 5D parallellism. The framework also integrates a chiplet cost model. The proposed modeling methodology provides valuable insights to guide future compute system design and facilitates hardware-software co-development, in particular due to its ability to analyze performance-cost trade-offs for various system architectural configurations.

cs.AR↗

arXiv2024

Calibrating DRAMPower Model for HPC: A Runtime Perspective from Real-Time Measurements

Main memory's rising energy consumption has emerged as a critical challenge in modern computing architectures, particularly in large-scale systems, driven by frequent access patterns, growing data volumes, and insufficient power management strategies. Accurate modeling of DRAM power consumption is essential to address this challenge and optimize energy efficiency. However, existing modeling tools often rely on vendor-provided datasheet values that are obtained under worst-case or idealized conditions. As a result, they fail to capture important system-level factors, such as temperature variations, chip aging, and workload-induced variability, which leads to significant discrepancies between estimated and actual power consumption observed in real deployments. In this work, we propose a runtime calibration methodology for the DRAMPower model using energy measurements collected from real-system experiments. By applying custom memory benchmarks on an HPC cluster and leveraging fine-grained power monitoring infrastructure, we refine key current parameters (IDD values) in the model. Our calibration reduces the average energy estimation error to less than 5%, substantially improving modeling accuracy and making DRAMPower a more reliable tool for power-aware system design and optimization on the target server platform.

cs.AR↗