Real Time FPGA Based Transformers & VLMs for Vision Tasks: SOTA Designs and Optimizations

Abstract

Transformers and vision-language models (VLMs) have emerged as dominant architectures in computer vision and multimodal AI, offering state-of-the-art performance in tasks such as image classification, object detection, visual question answering, and caption generation. However, their high computational complexity, large memory footprints, and irregular data access patterns present significant challenges for deployment in latency- and power-constrained environments. Field-programmable gate arrays (FPGAs) provide an attractive hardware platform for such workloads due to their reconfigurability, fine-grained parallelism, and potential for energy-efficient acceleration. This paper presents a comprehensive review of design trade-offs, optimization strategies, and implementation challenges for FPGA-based inference of transformers and VLMs. We examine critical factors such as device-class selection, memory subsystem constraints, dataflow orchestration, quantization strategies, sparsity exploitation, and toolchain choices, alongside modality-specific issues unique to VLMs, including heterogeneous compute balancing and cross-attention memory management. Additionally, we discuss emerging trends in hardware-algorithm co-design, highlighting innovations in attention mechanisms, compression, and modular overlays to improve efficiency and adaptability. Practical issues such as runtime flexibility, verification overhead, and the absence of standardized FPGA multimodal benchmarks are also considered. Finally, we outline future directions toward scalable, portable, and reconfigurable FPGA solutions that adapt to evolving model architectures while sustaining high utilization and predictable performance. This synthesis offers both a technical foundation and a forward-looking perspective to help bridge the gap between advanced multimodal AI models and efficient FPGA deployment.