Jul 2026· ACM Transactions on Architecture and Code Optimization (TACO)· Vol 23, pp. 1-25· 0 citations· 54 references
TL;DR
A bandwidth-oriented memory allocation mechanism, named AdaptiveKV, which is self-adaptive to CXL-enabled memory pools and KV cache offloading scales for LLM inference acceleration, and achieves a maximum speedup in LLM inference throughput compared to the state-of-the-art strategies.
Abstract
The explosive growth of key-value (KV) cache size in large language model (LLM) inference poses a key challenge to the limited HBM of GPU. Offloading KV cache to host memory has become a prevalent mitigation method. However, the limited host DDR bandwidth, especially in multi-GPU inference scenarios, often leads to offloading bottlenecks, thereby restricting inference speed. Compute express link (CXL) offers a promising alternative to expand host memory capacity and bandwidth on demand. In this paper, we present a bandwidth-oriented memory allocation mechanism, named AdaptiveKV, which is self-adaptive to CXL-enabled memory pools and KV cache offloading scales for LLM inference acceleration. Our systematic profiling of CXL-HBM memory bandwidth under GPU workloads reveals that conventional memory strategies neglect dynamic memory bandwidth fluctuations and various CXL memory characteristics, leading to suboptimal memory utilization. Motivated by these insights, AdaptiveKV implements three core designs: 1) a GPU memory conch model to guide memory allocation strategies, 2) a runtime predictor to predict optimal memory allocation ratios, and 3) a dynamic interleaving strategy to allocate memory pages across available NUMA nodes. Experimental results suggest that AdaptiveKV achieves a maximum speedup of 1.90 × in LLM inference throughput compared to the state-of-the-art strategies. To further explore AdaptiveKV’s applicability boundary, we also present an FPGA-based CXL memory emulator with configurable performance, revealing that a CXL-to-DDR bandwidth ratio exceeding 8% yields at least a 5% speedup in LLM inference.
This work presents Oneiros, a dynamic remapping engine for multi-tenant LLM serving that dynamically repurposes GPU memory allocated for model parameters as KV cache capacity, enabling nonblocking, unidirectional parameter transfer.
OasisKV is presented, a memory-centric LLM inference system design that alleviates HBM capacity pressure by decoupling full KV-cache storage from HBM during LLM decoding and observes that future important tokens can be predicted accurately in advance using lookahead tokens drafted by speculative decoding (SD).
Can Xiao, Sukmin Cho, Junbong We et al.· 0 citations
FlashAccel integrates HBF into HBM-based GPUs, providing architectural support to mitigate access latency and introduces an HBF-aware storage management layer together with a programming model to organize persistent data in HBF and coordinate heterogeneous memory resources at the system level.
Xinyu Wang, Yalong Xue, Xiaotian Sun et al.· 1 citation
LLM inference at scale faces a memory wall. The KV cache demands tens of terabytes at hundreds of gigabytes per second, yet no current memory tier delivers both at once. Characterization across multi-generation GPU systems with various LLaMA models shows host memory retrieval achieves up to 100x speedup over re-computation but supports only tens of concurrent long-context users. Electrical CXL pooling theoretically bridges this gap, but switch latency, cable reach limits, and power-scaling issues prevent practical TB-scale deployments. We present the Marvell Photonic Fabric Memory Appliance, a photonic-CXL hybrid architecture replacing electrical switches with a passive fiber shuffle to deliver 32 TB shared memory across 16 hosts via a switch-free full- crossbar topology. Emulation results demonstrate over 50 percent latency reduction versus electrical CXL pools. Simulation results show that the PF Memory Appliance eliminates cache eviction cliffs by improving time-to-first-token by 6.6x for multi-turn conversations workloads.
Jing Ding, Yash Nishant, Chandrish Ambati et al.· 0 citations
Scaling inference for large language models is increasingly constrained by limited GPU memory, primarily due to the expanding intermediate states (KV caches) required for long-context generation and multi-user workloads. Once the KV cache exceeds the capacity of high-bandwidth memory, it must be offloaded to host memory and reloaded on demand, a workflow severely bottlenecked by the CPU–GPU interconnect, typically PCIe. Existing approaches exploiting offload KV caches to CPU memory and selectively reload partial segments for attention computation often underutilize CPU compute resources and suffer from accuracy degradation. We present Beyond, a drop-in runtime that integrates a smart offloading scheme to selectively identify and retain salient KV entries across continuous decoding sessions, together with a hybrid CPU–GPU attention mechanism for scalable inference. Beyond executes dense attention over recent KV entries stored in GPU memory while performing parallel, per-head sparse attention on salient contextual KV entries residing in CPU memory. The outputs are fused efficiently through a log-sum-exp scheme. During the bandwidth-constrained decoding phase, oversized KV caches are processed cooperatively by the aggregated CPU and GPU memory bandwidth, with only minimal PCIe data movement. Experiments across diverse models and workloads demonstrate that Beyond improves scalability, supports longer sequences and larger batch sizes, and outperforms existing sparse attention baselines in both efficiency and accuracy—all on commodity GPU hardware.
Weishu Deng, Yujie Yang, Peiran Du et al.· IEEE International Symposium...· 1 citation