In plain words: GPUs can copy data in the background while their cores compute, but only for big chunks. Hidden AMD GPU features extend this to tiny KB-sized messages, up to 4.5× faster than plain background copying, and beat the usual GPU-core communication library while saving power.
Abstract · DMA-Latte: Expanding the Reach of DMA Offloads to Latency-bound ML Communication
Offloading communication to existing direct memory access (DMA) engines, available on most state-of-the-art commercial GPUs, has emerged as a practical and low-cost solution to efficiently overlap computation and communication in machine learning (ML). However, the reach of DMA offloads has so far been limited to bandwidth-bound scenarios only (10s of MB to GB transfer sizes). In this work, we break this barrier and extend DMA communication offloads to latency-bound regions (KB to low MB). Specifically, we leverage hitherto untapped features available in the state-of-the-art AMD Instinct$^{\mathrm{TM}}$ GPUs that render DMA communication offloads competitive even in latency-bound regions. We demonstrate the efficacy of these features both at the operator level (ML communication collectives such as all-gather and all-to-all), and at the end-to-end workload level (LLM inference). At the operator level, our optimizations provide up to 4.5$\times$ speedups (3.2$\times$ geomean in the latency-bound region) over baseline DMA offload, narrowing the performance gap while delivering additional power savings (3-10%) for ML collectives compared to state-of-the-art GPU core-based communication library, RCCL. At the workload level, we demonstrate acceleration for LLM inference: up to 1.65$\times$ lower latency and up to 1.9$\times$ higher throughput over the state-of-the-art vLLM inference framework. We conclude with a discussion of AMD Instinct GPU runtime innovations that stand to expose these features.
Suchita Pati, Shaizeen Aga, Mahzabeen Islam, Ryan Quach, Saleel Kudchadker, Mohamed Assem Ibrahim
arXiv:2511.06605 · cs.DC, cs.AR · submitted Nov 10, 2025 · updated Sep 14, 2026
abstract · pdf · html · Accepted to appear in the 59th IEEE/ACM International Symposium on Microarchitecture (MICRO 2026)