# CXL-SpecKV: A Disaggregated FPGA Speculative KV-Cache for Datacenter LLM Serving

arXiv: https://arxiv.org/abs/2512.11920 · HTML: https://mlsanity.com/paper/2512.11920/

## Key facts

- Cited by 8 papers in the map (data through 14 Oct 2026).
- Placed in KV cache optimization, one of 12 directions in Efficient LLM inference and serving.
- Builds on 20 of its 48 references that are in the map.
- First posted on arXiv 11 Dec 2025.

## Placed in

- Efficient LLM inference and serving / [KV cache optimization](https://mlsanity.com/inference/kv-cache-optimization/)

## Builds on (most cited first, 20 of 20)

- [Language Models are Few-Shot Learners](https://mlsanity.com/paper/2005.14165/) (2020)
- [The Llama 3 Herd of Models](https://mlsanity.com/paper/2407.21783/) (2024)
- [Efficient Memory Management for Large Language Model Serving with PagedAttention](https://mlsanity.com/paper/2309.06180/) (2023)
- [SQuAD: 100,000+ Questions for Machine Comprehension of Text](https://mlsanity.com/paper/1606.05250/) (2016)
- [Qwen Technical Report](https://mlsanity.com/paper/2309.16609/) (2023)
- [Efficient Streaming Language Models with Attention Sinks](https://mlsanity.com/paper/2309.17453/) (2023)
- [Fast Inference from Transformers via Speculative Decoding](https://mlsanity.com/paper/2211.17192/) (2022)
- [SmoothQuant: Accurate and Efficient Post-Training Quantization for Large Language Models](https://mlsanity.com/paper/2211.10438/) (2022)
- [DeepSeek-V2: A Strong, Economical, and Efficient Mixture-of-Experts Language Model](https://mlsanity.com/paper/2405.04434/) (2024)
- [Medusa: Simple LLM Inference Acceleration Framework with Multiple Decoding Heads](https://mlsanity.com/paper/2401.10774/) (2024)
- [H2O: Heavy-Hitter Oracle for Efficient Generative Inference of Large Language Models](https://mlsanity.com/paper/2306.14048/) (2023)
- [Abstractive Text Summarization Using Sequence-to-Sequence RNNs and Beyond](https://mlsanity.com/paper/1602.06023/) (2016)
- [KIVI: A Tuning-Free Asymmetric 2bit Quantization for KV Cache](https://mlsanity.com/paper/2402.02750/) (2024)
- [KVQuant: Towards 10 Million Context Length LLM Inference with KV Cache Quantization](https://mlsanity.com/paper/2401.18079/) (2024)
- [FlexGen: High-Throughput Generative Inference of Large Language Models with a Single GPU](https://mlsanity.com/paper/2303.06865/) (2023)
- [DeepSpeed Inference: Enabling Efficient Inference of Transformer Models at Unprecedented Scale](https://mlsanity.com/paper/2207.00032/) (2022)
- [Learning Memory Access Patterns](https://mlsanity.com/paper/1803.02329/) (2018)
- [TinyServe: Query-Aware Cache Selection for Efficient LLM Serving](https://mlsanity.com/paper/2509.12211/) (2025)
- [CSV-Decode: Certifiable Sub-Vocabulary Decoding for Efficient Large Language Model Inference](https://mlsanity.com/paper/2511.21702/) (2025)
- [Systolic Sparse Tensor Slices: FPGA Building Blocks for Sparse and Dense AI Acceleration](https://mlsanity.com/paper/2502.03763/) (2025)

## Built on by (most cited first, 8 of 8)

- [Towards Efficient Large Language Model Serving: A Survey on System-Aware KV Cache Optimization](https://mlsanity.com/paper/2607.08057/) (2026)
- [AdaCorrection: Adaptive Offset Cache Correction for Accurate Diffusion Transformers](https://mlsanity.com/paper/2602.13357/) (2026)
- [MedRAGChecker: Claim-Level Verification for Biomedical Retrieval-Augmented Generation](https://mlsanity.com/paper/2601.06519/) (2026)
- [Accelerating Frequency Domain Diffusion Models with Error-Feedback Event-Driven Caching](https://mlsanity.com/paper/2604.22901/) (2026)
- [Predictive Multi-Tier Memory Management for KV Cache in Large-Scale GPU Inference](https://mlsanity.com/paper/2604.26968/) (2026)
- [Thoughts-as-Planning: Latent World Models for Chain-of-Thoughts Optimization via Reinforcement Planning](https://mlsanity.com/paper/2605.28842/) (2026)
- [From Tensor Buffer to Distributed Memory Hierarchy: A Survey of KV Cache Management for LLM Serving](https://mlsanity.com/paper/2607.02574/) (2026)
- [MeshKV: A Network-on-Chip KV Cache Fabric for Scalable Transformer Decoding Accelerators](https://mlsanity.com/paper/2609.19207/) (2026)

## Abstract (arXiv)

Large Language Models (LLMs) have revolutionized natural language processing tasks, but their deployment in datacenter environments faces significant challenges due to the massive memory requirements of key-value (KV) caches. During the autoregressive decoding process, KV caches consume substantial GPU memory, limiting batch sizes and overall system throughput. To address these challenges, we propose CXL-SpecKV, a novel disaggregated KV-cache architecture that leverages Compute Express Link (CXL) interconnects and FPGA accelerators to enable efficient speculative execution and memory disaggregation. Our approach introduces three key innovations: (i) a CXL-based memory disaggregation framework that offloads KV-caches to remote FPGA memory with low latency, (ii) a speculative KV-cache prefetching mechanism that predicts and preloads future tokens' cache entries, and (iii) an FPGA-accelerated KV-cache compression and decompression engine that reduces memory bandwidth requirements by up to 4×. When evaluated on state-of-the-art LLM models, CXL-SpecKV achieves up to 3.2× higher throughput compared to GPU-only baselines, while reducing memory costs by 2.8× and maintaining accuracy. Our system demonstrates that intelligent memory disaggregation combined with speculative execution can effectively address the memory wall challenge in large-scale LLM serving. Our code implementation has been open-sourced at https://github.com/FastLM/CXL-SpecKV.