Vela: A Virtualized LLM Training System with GPU Direct RoCE
Vela is a cloud-native system designed for LLM training workloads built using off-the-shelf hardware, Linux KVM-based virtualization, and a virtualized RDMA over Converged Ethernet (RoCE) network. Vela virtual machines (VMs) support peer-to-peer DMA between the GPUs and SRIOV-based network interface. In this paper, we share Vela's key architectural aspects with details from an NVIDIA A100 GPU-based deployment in one of the IBM Cloud data centers. Throughout the paper, we share insights and experiences from designing, building, and operating the system over a ~2.5 year timeframe to highlight the capabilities of readily available software and hardware technologies and the improvement opportunities for future AI systems, thereby making AI infrastructure more accessible to a broader community. As we evaluated the system for performance at ~1500 GPU scale, we achieved ~80% of the ideal throughput while training a 50 billion parameter decoder model using model parallelism, and ~70% per GPU FLOPS compared to a single VM with the High-Performance Linpack benchmark.
Authors
- Sandhya Koteshwara (ORCID: https://orcid.org/0000-0003-3182-219X)
- Talia Gershon (ORCID: https://orcid.org/0000-0001-9408-1080)
- M.B. Dombrowa
- Liran Schour (ORCID: https://orcid.org/0000-0002-6163-0060)
- Seetharami Seelam (ORCID: https://orcid.org/0000-0002-7595-3477)
- Sophia Wen
- Shweta Salaria
- Abdullah Kayi (ORCID: https://orcid.org/0000-0001-5909-9891)
- Vasily Tarasov (ORCID: https://orcid.org/0000-0003-1424-9977)
- Rei Odaira
- Pavlos Maniotis
- R. E. Walkup
- Md. Abdul Alim (ORCID: https://orcid.org/0000-0002-8557-6783)
- Laurent Schares (ORCID: https://orcid.org/0000-0002-9506-8467)
- Apoorve Mohan (ORCID: https://orcid.org/0000-0003-3789-5453)
- Ming-Hung Chen (ORCID: https://orcid.org/0000-0002-6946-2313)
- Constantinos Evangelinos (ORCID: https://orcid.org/0000-0002-7906-8651)
- Eran Gampel
- Ali Sydney (ORCID: https://orcid.org/0000-0003-4410-2175)
- Drew Thorstensen
- Joel Belog
- Lixiang Luo
- I‐Hsin Chung (ORCID: https://orcid.org/0000-0003-4555-9257)
- Bengi Karaçali
- Brent Tang
Institutions
- University of Massachusetts Lowell (US)
- IBM (United States) (US)
- IBM Research - Almaden (US)
- Cambridge Scientific (United States) (US)
- Cloud Pharmaceuticals (United States) (US)
- IBM Research - Haifa (IL)
Publication Details
- Published
- 2025-03-27
- DOI
- https://doi.org/10.1145/3676641.3716280
- Citations
- 2
- Primary Topic
- Cloud Computing and Resource Management
- Type
- article
- Field-Weighted Citation Impact
- 6.49