CXLRAMSim v1.0: System-Level Exploration of CXL Memory Expander Cards

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Pathak, Karan, Atienza, David, Zapater, Marina
Format: Preprint
Publié: 2026
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866914434279014400
author Pathak, Karan
Atienza, David
Zapater, Marina
author_facet Pathak, Karan
Atienza, David
Zapater, Marina
contents The growing demands in the training and inference of Large Language Models (LLMs) are accelerating the adoption of scale-up systems that extend server shared memory through the use of Compute Express Link (CXL)-based load/store interconnects. Accurate full-system simulation of such architectures remains challenging, as existing tools (all very recent) rely on simplified or non-compliant architectural models, impacting accuracy and usability. We present CXLRAMSim, the first gem5-integrated, full-system simulator that models CXL devices at their correct position on the I/O bus, enabling the use of unmodified Linux kernels and software stack, realistic latency-bandwidth behavior and true interleaving with system DRAM. Our approach provides high-fidelity CXL.mem characterization and captures key challenges such as cache pollution when accessing CXL memory.
format Preprint
id arxiv_https___arxiv_org_abs_2603_29483
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle CXLRAMSim v1.0: System-Level Exploration of CXL Memory Expander Cards
Pathak, Karan
Atienza, David
Zapater, Marina
Hardware Architecture
Emerging Technologies
The growing demands in the training and inference of Large Language Models (LLMs) are accelerating the adoption of scale-up systems that extend server shared memory through the use of Compute Express Link (CXL)-based load/store interconnects. Accurate full-system simulation of such architectures remains challenging, as existing tools (all very recent) rely on simplified or non-compliant architectural models, impacting accuracy and usability. We present CXLRAMSim, the first gem5-integrated, full-system simulator that models CXL devices at their correct position on the I/O bus, enabling the use of unmodified Linux kernels and software stack, realistic latency-bandwidth behavior and true interleaving with system DRAM. Our approach provides high-fidelity CXL.mem characterization and captures key challenges such as cache pollution when accessing CXL memory.
title CXLRAMSim v1.0: System-Level Exploration of CXL Memory Expander Cards
topic Hardware Architecture
Emerging Technologies
url https://arxiv.org/abs/2603.29483