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LLM training and serving systems

The effective model includes its precision, partition, kernel, cache, scheduler, and request distribution. This route connects systems claims to measured evidence.

31 maintained papers · literature reviewed through 2 October 2026

Precision, sharding, tensor and pipeline parallelism, attention kernels, KV-cache management, speculative decoding, and quantization alter feasible batch, sequence, checkpoint, and latency regimes. Quality, memory, throughput, latency, communication, and reliability must be measured at a declared system point.

Prerequisite contract

How the field developed

  1. 2018–2021

    Precision and distributed state partitioning

    Mixed precision reduces arithmetic and memory cost; ZeRO partitions optimizer, gradient, and parameter states; Megatron combines tensor and pipeline parallelism.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    01.01Mixed Precision Training2018 · ICLR · Peer reviewedPaulius Micikevicius et al.Mixed-precision training uses FP16 tensors for most forward and backward computation, accumulates vulnerable arithmetic in FP32, and updates an FP32 master copy of weights before recasting them to FP16. Loss scaling protects small gradients from FP16 underflow. Together these safeguards preserve FP32-like accuracy while enabling faster, lower-memory arithmetic on supporting hardware.—
    01.02ZeRO: Memory Optimizations Toward Training Trillion Parameter Models2020 · SC · Peer reviewedSamyam Rajbhandari, Jeff Rasley, Olatunji Ruwase, and Yuxiong HeZeRO removes the replicated model-state memory hidden inside data parallel training. Its cumulative stages partition optimizer states, then gradients, then parameters across data-parallel workers while dynamically communicating each state when needed. ZeRO-R separately attacks residual memory from activation checkpoints, temporary buffers, and fragmentation. The result preserves large compute kernels while making aggregate cluster memory usable.DeepSpeed
    01.03Efficient Large-Scale Language Model Training on GPU Clusters Using Megatron-LM2021 · SC · Peer reviewedDeepak Narayanan et al.Megatron-LM composes three parallelism axes for large Transformer training: tensor parallelism splits operations inside a layer, pipeline parallelism assigns layer groups to stages, and data parallelism replicates whole model partitions across batches. The PTD-P arrangement keeps high-communication tensor collectives within fast multi-GPU servers, pipelines across servers, and uses an interleaved 1F1B schedule to shrink idle bubbles.Megatron-LM

    Work: Account for every parameter, gradient, optimizer state, activation, and communication edge.

    Exit evidence: Predict per-device memory and compare it with measured peak allocation.

  2. 2019–2025

    Distilled language- and multimodal-model deployment

    DistilBERT and MiniLM compress encoder pretraining states; MiniLLM and DistiLLM change the divergence and sampling policy for generation; MiniPLM refines the pretraining corpus offline; TAID adapts targets over time; LLaVA-MoD adds a sparse MoE student and preference distillation.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    02.01DistilBERT, a Distilled Version of BERT: Smaller, Faster, Cheaper and Lighter2019 · NeurIPS EMC² Workshop · Technical reportVictor Sanh, Lysandre Debut, Julien Chaumond, and Thomas WolfWorkshop paper and arXiv preprint; not a main-track NeurIPS proceedings paper.DistilBERT compresses BERT during language-model pretraining rather than only after task fine-tuning. A six-layer student initialized from alternating BERT-base layers learns from three simultaneous signals: the teacher token distribution, masked-token ground truth, and cosine alignment of hidden states. Removing half the Transformer blocks, token-type embeddings, and the pooler yields a 66M-parameter encoder intended to preserve much of BERT's general English representation at lower inference cost.Official distillation code
    02.02MiniLM: Deep Self-Attention Distillation for Task-Agnostic Compression of Pre-Trained Transformers2020 · NeurIPS · Peer reviewedWenhui Wang, Furu Wei, Li Dong, Hangbo Bao, Nan Yang, and Ming ZhouMiniLM compresses a pretrained Transformer before task-specific fine-tuning by matching relations inside the teacher's final self-attention layer. It distills both attention distributions and a newly defined value-relation matrix. Because supervision is taken from only the last layer, teacher and student may differ in depth and hidden size without hand-designed layer mapping.Official implementation and checkpoints
    02.03MiniLLM: Knowledge Distillation of Large Language Models2024 · ICLR · Peer reviewedYuxian Gu, Li Dong, Furu Wei, and Minlie HuangMiniLLM distills an autoregressive language model by minimizing reverse KL from the student sequence distribution to the teacher. The student generates its own responses, the teacher scores those trajectories, and policy-gradient machinery moves probability toward teacher-supported sequences. Reverse KL is mode seeking: it discourages the student from assigning mass to low-teacher-probability outputs rather than forcing it to cover every teacher mode.Official code
    02.04DistiLLM: Towards Streamlined Distillation for Large Language Models2024 · ICML · Peer reviewedJongwoo Ko, Sungnyun Kim, Tianyi Chen, and Se-Young YunPeer-reviewed ICML 2024 proceedings paper.DistiLLM targets two coupled failures in autoregressive language-model distillation: unstable token-distribution matching and train/test exposure mismatch. It replaces ordinary forward or reverse KL with skew KL divergences whose mixture reference controls estimator behavior, then adaptively trains on student-generated sequences and reuses recent generations through an off-policy buffer. The student therefore learns both from fixed instruction data and from states its own policy is likely to visit.Official code
    02.05TAID: Temporally Adaptive Interpolated Distillation for Efficient Knowledge Transfer in Language Models2025 · ICLR · Peer reviewedMakoto Shing, Kou Misaki, Han Bao, Sho Yokoi, and Takuya AkibaTAID bridges a large language-model capacity gap by moving the student's target gradually from its own current distribution toward the teacher. At early steps, the interpolated target remains close to a detached student and is easy to fit; as learning stabilizes, the interpolation coefficient increases and exposes more teacher knowledge. The schedule adapts to objective progress instead of following only wall-clock training.Official code
    02.06MiniPLM: Knowledge Distillation for Pre-Training Language Models2025 · ICLR · Peer reviewedYuxian Gu, Hao Zhou, Fandong Meng, Jie Zhou, and Minlie HuangPeer-reviewed ICLR 2025 conference paper.MiniPLM moves language-model distillation out of the training loss and into pretraining-data selection. A large teacher and a much smaller reference model score each candidate sequence; examples with high log pteacher(x) − log preference(x) are selected, and any student is then trained from scratch with ordinary next-token prediction. Knowledge transfer becomes a reusable ranked corpus rather than stored token logits or a teacher loaded beside every student update.Official code, data, and models
    02.07LLaVA-MoD: Making LLaVA Tiny via MoE-Knowledge Distillation2025 · ICLR · Peer reviewedFangxun Shu, Yue Liao, Lei Zhang, Le Zhuo, Chenning Xu, Guanghao Zhang, Haonan Shi, Long Chen, Tao Zhong, Wanggui He, Siming Fu, Haoyuan Li, Zhelun Yu, Si Liu, Hongsheng Li, and Hao JiangPeer-reviewed ICLR 2025 conference paper.LLaVA-MoD builds a compact multimodal language model by combining sparse mixture-of-experts capacity with progressive knowledge distillation. A dense small Qwen-family MLLM first mimics general teacher behavior, its feed-forward blocks are then upcycled into routed experts for specialized multi-task transfer, and preference distillation finally pushes positive responses above and negative responses below the large teacher's relative likelihood. Only a subset of experts activates per token, so total capacity and inference compute must be reported separately.Official code

    Work: Deploy teacher and student checkpoints on one stack; separate online/offline teacher cost, pretraining/post-training transfer, activated/total parameters, and steady-state inference cost.

    Exit evidence: Report parameters, activated experts, memory, quality, calibration, prefill/decode latency, throughput, teacher amortization, and tokenizer compatibility.

  3. 2022–2023

    Attention kernels and serving memory

    FlashAttention reduces memory traffic with tiled exact attention; vLLM manages fragmented KV caches with PagedAttention.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    03.01FlashAttention: Fast and Memory-Efficient Exact Attention with IO-Awareness2022 · NeurIPS · Peer reviewedTri Dao et al.FlashAttention computes the same softmax attention output as standard attention but changes the execution schedule: it tiles Q, K, and V into on-chip SRAM, maintains online softmax statistics, and never materializes the full N×N score or probability matrix in high-bandwidth memory (HBM). It trades some recomputation for far fewer slow-memory transfers, making this an IO-aware exact algorithm rather than an approximate attention rule.—
    03.02Efficient Memory Management for Large Language Model Serving with PagedAttention2023 · SOSP · Peer reviewedWoosuk Kwon et al.vLLM applies a virtual-memory analogy to autoregressive serving: PagedAttention divides each request's growing key-value cache into fixed-size logical blocks and maps them to non-contiguous GPU physical blocks. Memory is allocated only when tokens arrive, so a request no longer reserves one maximum-length contiguous region. A central scheduler can fill the recovered memory with more concurrent requests, share prompt blocks through copy-on-write, and preempt under pressure. The 2023 claim is a systems result—higher serving throughput at comparable latency and unchanged model outputs—not a new language model or attention approximation.Serving system

    Work: Profile compute, memory bandwidth, cache occupancy, prefill, decode, and queueing separately.

    Exit evidence: Report latency distributions and throughput under an explicit request trace.

  4. 2023–2026

    Drafting and low-precision inference

    Speculative decoding verifies draft tokens; SmoothQuant moves activation difficulty into weights; AWQ protects salient weight channels without full reconstruction; SliderQuant adapts precision further.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    04.01Fast Inference from Transformers via Speculative Decoding2023 · ICML · Peer reviewedYaniv Leviathan, Matan Kalman, and Yossi MatiasSpeculative decoding uses a cheap draft model to propose several autoregressive tokens, evaluates all corresponding prefixes in one parallel target-model call, accepts each proposal with a probability determined by the target-to-draft probability ratio, and samples a correction from the positive residual at the first rejection. If every draft is accepted, it draws one additional target token. This draft-many, verify-once pattern can turn one serial target step into as many as gamma plus one output tokens while preserving the target model's standardized output distribution exactly.—
    04.02SmoothQuant: Accurate and Efficient Post-Training Quantization for Large Language Models2023 · ICML · Peer reviewedGuangxuan Xiao et al.SmoothQuant makes full W8A8 post-training quantization practical for large transformers by applying an offline, mathematically equivalent channel scaling: it suppresses persistent activation outliers and moves part of their dynamic-range burden into weights, which are empirically easier to quantize. The transformed linear layer computes the same floating-point function before rounding, so runtime can use regular INT8 matrix multiplications rather than a mixed FP16 outlier path.Code
    04.03AWQ: Activation-Aware Weight Quantization for On-Device LLM Compression and Acceleration2024 · MLSys · Peer reviewedJi Lin, Jiaming Tang, Haotian Tang, Shang Yang, Wei-Ming Chen, Wei-Chen Wang, Guangxuan Xiao, Xingyu Dang, Chuang Gan, and Song HanAWQ is a post-training, weight-only quantization method that protects weight channels identified as salient by activation magnitude. Rather than keeping those channels in higher precision, it rescales weights and inversely rescales activations before low-bit quantization so the exact floating-point layer is unchanged but quantization error is redistributed. TinyChat then realizes the memory reduction as speed through fused dequantization and device-aware kernels.Official project page · Official implementation and model zoo
    04.04SliderQuant: Accurate Post-Training Quantization for LLMs2026 · ICLR · Peer reviewedShigeng Wang, Chao Li, Yangyuxuan Kang, Jiawei Fan, Zhonghong Ou, and Anbang YaoPeer-reviewed ICLR 2026 poster; retain as a frontier quantization method after systems and quantization foundations.SliderQuant replaces uniform sequential post-training quantization with an adaptive overlapping-window schedule. It repeatedly includes the sensitive first layer while expanding through shallow layers, uses fixed overlapping windows through the middle, contracts toward the sensitive last layer, and incrementally quantizes parameter slices inside each window. The goal is to optimize cross-layer error where the paper observes it matters most, especially under W4A4 and two-bit weight settings.Code

    Work: Hold outputs or quality tolerance fixed while measuring calibration, memory, kernels, and end-to-end serving cost.

    Exit evidence: Publish acceptance, quantization error, fallback, memory, and quality-by-latency curves.

  5. 2024

    Disaggregated serving and structured generation runtimes

    DistServe separates prefill and decode to satisfy per-phase latency objectives; SGLang exposes a structured generation language and RadixAttention runtime for prefix sharing and scheduling.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    05.01DistServe: Disaggregating Prefill and Decoding for Goodput-Optimized Large Language Model Serving2024 · OSDI · Peer reviewedYinmin Zhong, Shengyu Liu, Junda Chen, Jianbo Hu, Yibo Zhu, Xuanzhe Liu, Xin Jin, and Hao ZhangDistServe places LLM prefill and autoregressive decoding on separate GPU pools so compute-heavy prompt processing cannot interrupt bandwidth-heavy token generation. It independently chooses parallelism and replica counts for the two phases, transfers the first-token state and KV cache between them, and places matching model stages near one another. The optimization target is per-GPU goodput: maximum request arrival rate that meets both time-to-first-token and time-per-output-token SLOs at a required attainment fraction.Official implementation
    05.02SGLang: Efficient Execution of Structured Language Model Programs2024 · NeurIPS · Peer reviewedLianmin Zheng, Liangsheng Yin, Zhiqiang Xie, Chuyue Sun, Jeff Huang, Cody Hao Yu, Shiyi Cao, Christos Kozyrakis, Ion Stoica, Joseph E. Gonzalez, Clark Barrett, and Ying ShengSGLang couples a Python-embedded language for structured language-model programs with a specialized runtime that exploits structure across requests and program steps. The frontend expresses generation, parallel branches, control flow, external functions, and multimodal inputs. The runtime interprets those operations, reuses shared KV-cache prefixes through RadixAttention, accelerates constrained decoding with compressed finite-state machines, and can speculatively execute API calls.Official implementation

    Work: Replay the same request trace while varying prefill/decode placement, prefix reuse, batching, and admission control.

    Exit evidence: Report time-to-first-token, inter-token latency, throughput, cache hit rate, utilization, and SLO attainment.

  6. 2025–2026

    Native sparsity and stateful sequence modules

    Native Sparse Attention co-designs trainable sparse attention with hardware-aligned kernels. TTT Layers makes the recurrent hidden state a fast-weight model updated by a learned self-supervised rule; Modular TTT then expresses that inner learner as a configurable DAG of fast-weight network, loss, learning rate, weight decay, and normalization.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    06.01Native Sparse Attention: Hardware-Aligned and Natively Trainable Sparse Attention2025 · ACL · Peer reviewedJingyang Yuan et al.ACL 2025 Best Paper.Native Sparse Attention replaces one full causal attention map with three jointly trained views of the prefix. A compression branch summarizes overlapping blocks for global coverage; those compression scores nominate a small set of contiguous fine-grained blocks; and a sliding-window branch preserves recent detail. Separate key/value projections and learned gates combine the three outputs. Crucially, the sparse pattern is used during pretraining, prefilling, decoding, and backpropagation, and the selection granularity is chosen for contiguous Tensor-Core-friendly memory access rather than theoretical sparsity alone.—
    06.02Learning to (Learn at Test Time): RNNs with Expressive Hidden States2025 · ICML · Peer reviewedYu Sun, Xinhao Li, Karan Dalal, Jiarui Xu, Arjun Vikram, Genghan Zhang, Yann Dubois, Xinlei Chen, Xiaolong Wang, Sanmi Koyejo, Tatsunori Hashimoto, and Carlos GuestrinA TTT layer makes its recurrent hidden state a small machine-learning model. For every input sequence, that inner model is updated online with a learned self-supervised objective and then queried to emit token representations. The slow network learns how to construct the inner task; the fast weights learn from the current sequence. TTT-Linear uses a linear inner model and TTT-MLP uses a two-layer MLP, retaining constant state size and linear sequence complexity.Official code
    06.03Modular TTT: Rethinking Test-Time Training as Composable Modules2026 · arXiv · PreprintBohao Tang, Zhen Qin, Yuqi Pan, Zheng Li, Pengfei Liu, and Ya ZhangPreprint status retained; no peer-reviewed proceedings record was available when checked on 2026-08-10.Modular TTT represents a test-time-training memory as a directed acyclic graph rather than a separately hand-derived layer. Each node registers three local rules—train-view forward, train-view backward, and causal query-view forward—and the framework composes them into a chunk-level online learner whose fast weights change while a sequence is processed. This makes the fast network, loss, learned inner learning rate, forgetting rule, activation, and normalization independently swappable design axes.Official code

    Work: Match quality, context length, training tokens, hardware, and precision before comparing dense attention, native sparsity, and stateful adaptation.

    Exit evidence: Report both algorithmic complexity and measured training/prefill/decode curves.

  7. 2024–2026

    Prune, distil, and audit causal serving

    Minitron couples structured pruning with KD; GISP builds nested globally ranked subnetworks; prefix-invariance auditing detects information paths that a nominal causal mask may miss. Structural sparsity still requires backend timing.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    07.01Compact Language Models via Pruning and Knowledge Distillation2024 · NeurIPS · Peer reviewedSaurav Muralidharan, Sharath Turuvekere Sreenivas, Raviraj Joshi, Marcin Chochowski, Mostofa Patwary, Mohammad Shoeybi, Bryan Catanzaro, Jan Kautz, and Pavlo MolchanovPublished in the NeurIPS 2024 main conference proceedings.Core mechanism: structured pruning followed by distillation. Minitron derives smaller language models by removing transformer depth, hidden dimensions, attention heads, or MLP channels from a pretrained base, initializing the child with retained weights, and recovering quality through knowledge distillation on a small fraction of pretraining data. This reading boundary matters: the recipe amortizes one expensive pretraining run into related compact checkpoints, not a claim that arbitrary architectures can be pruned without architecture- and data-specific recovery.Official implementation · Official model collection
    07.02From Local to Global: Revisiting Structured Pruning Paradigms for Large Language Models2026 · ACL · Peer reviewedZiyan Wang, Enmao Diao, Qi Le, Pu Wang, Minwoo Lee, Shu-ping Yeh, Evgeny Stupachenko, Hao Feng, and Li YangPeer-reviewed ACL 2026 long paper and Outstanding Paper award recipient.GISP prunes structured units by comparing their importance globally across the whole language model, then removes them gradually rather than in one destructive step. First-order loss sensitivity is aggregated into attention-head and MLP-channel scores, normalized within structure types, and globally ranked. Recomputing those scores after each small pruning step yields a sequence of nested subnetworks at many usable sparsity levels without parameter fine-tuning.Author manuscript
    07.03The Mask Is Not the Model: Auditing Prefix Invariance in Attention, State-Space, and Hybrid Sequence Models2026 · arXiv · PreprintTaebong Kim, Youngsik Hong, Minsik Kim, Sunyoung Choi, Jaewon Jang, and Minseo KimarXiv preprint first submitted 24 August 2026; not peer reviewed as of the audit date.The audit tests prefix invariance: in a correct causal sequence model, outputs for an existing prefix must not change when unseen suffix tokens are appended. AX-RAY runs only two forward passes—one on a prefix and one on prefix plus suffix—then compares overlapping positions layer by layer. This catches information leaks outside the visible attention mask, including state-space scans, normalization, and hybrid residual paths, without gradients or a reference model.Official AX-RAY demo

    Work: Prune and distil one model into fixed and nested capacity points, then audit prefix invariance at each checkpoint and measure end-to-end prefill/decode latency on the same hardware and software stack.

    Exit evidence: Report total and active parameters, pruning rule, KD data and teacher cost, subnet switching, memory, throughput, latency distribution, output quality, and causal-mask violations.

  8. 2026

    Residual distillation, bounded attention, and low-cost pretraining

    Residual-learning LLM KD and ACTD address hidden-state or vocabulary mismatch; sliding-window supplies a cheap retrofit baseline; Puro-2B makes the pretraining hardware and cost ledger inspectable.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    08.01Knowledge Distillation for Large Language Models through Residual Learning2026 · ICLR · Peer reviewedThinh On, Hengzhi Pei, Leonard Lausen, and George KarypisPublished at ICLR 2026; no official implementation was located by 2026-09-02.This ICLR 2026 method distills LLMs by emphasizing tokens where the teacher errs and representing the student's hidden state relative to a compressed teacher state. A pretrained teacher autoencoder, adaptive scaling, cross-tokenizer alignment, and mixture-of-experts fusion let residual supervision operate even when teacher and student vocabularies differ.OpenReview record · First-party Amazon Science page
    08.02ACTD: Anchor-Based Cross-Tokenizer Distillation with Residual Regularization2026 · EMNLP · Accepted · proceedings pendingHuiyi Zhang, Zijian Li, Xiaocheng Feng, Weitao Ma, Xiaoliang Yang, Yichong Huang, and Bing QinThe arXiv record reports acceptance to the EMNLP 2026 main conference. No final ACL Anthology proceedings record was available at the 2026-09-02 audit, so methods and results remain pinned to arXiv v1 submitted 30 August 2026.ACTD distills reasoning models across different tokenizers by mapping teacher top-k tokens into student-space anchors. An anchor L1 term matches probability on aligned tokens, while residual regularization constrains the student's probability mass outside those anchors. With multiple teachers, ACTD computes a complete teacher-specific loss for each teacher and averages those losses; it does not average anchor signals or teacher distributions first.Official implementation
    08.03Sliding-window beats linear attention2026 · arXiv · PreprintAlexia Jolicoeur-Martineau, Rhea Sanjay Sukthanker, Pashmina Cameron, and Emy GervaisarXiv v1 submitted 28 August 2026. No peer-reviewed record, code release, or model artifact was verified on 2 September 2026; it is retained for its unusually important negative baseline evidence rather than publication status.Core result: a training-free sliding-window attention baseline with four attention sinks matches or exceeds the reported post-trained linear-attention retrofits on ordinary language benchmarks, speed, memory, and the tested long-context tasks. The scientific contribution is therefore a negative baseline result: before paying to linearize an existing LLM, compare against an equally bounded sliding window.—
    08.04Puro-2B: Poor Lab's Qwen2-1.5B Trained on RTX 5090 within $50902026 · arXiv · PreprintKairong Luo, Jiarui Cui, Yaorui Yin, Shengqi Chen, Yiming Yang, Linxiang Gao, Yanmohan Wang, Mingzhe Zhang, Kaiyue Wen, Kaifeng Lyu, and Wenguang ChenarXiv v1 submitted 27 August 2026. Catalog authors follow the current arXiv metadata; the PDF title page additionally names Chengxia Li, an unresolved source-metadata discrepancy that should be rechecked on revision. Code, data, and checkpoints were released, but no peer-reviewed record was verified.Core idea: make a complete two-billion-parameter pretraining stack reproducible on consumer RTX 5090 clusters, then publish the measured token, GPU-hour, rental-rate, data, optimization, checkpoint, and evaluation ledgers. The result is not literally a 5,090-dollar canonical run: the full 1.4-trillion-token checkpoint costs an estimated USD 6.89K, while a fitted recipe-specific scaling law crosses the Qwen2-1.5B score near USD 4.4K.Official training implementation · Official models and data collection

    Work: Account for teacher forward/state cost, tokenizer mapping, training tokens, KV memory, hardware utilization, and deployed prefill/decode latency.

    Exit evidence: Compare quality at matched end-to-end cost, context, precision, and released implementation state.

  9. 2025–2026

    Frequency-domain visual token budgets

    Fourier Compressor uses fixed DCT truncation on feature grids, followed by VLM adaptation. Distinguish parameter-free compression from training-free deployment, and average retention from fine-detail fidelity.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    09.01Fourier Compressor: Frequency-Domain Visual Token Compression for Vision-Language Models2026 · ECCV · Accepted · proceedings pendingHuanyu Wang, Jushi Kai, Haoli Bai, Lu Hou, Bo Jiang, Ziwei He, Zhouhan LinECCV 2026 spotlight verified from the official linked program event. Review uses the conference-hosted manuscript checked 2026-09-12; a separate Springer version of record was not verified. Parameter-free compression is NOT training-free: Section 5.1 and Table 2 require adaptation. The 31.2% number concerns reduced time to first token, not a measured 31.2% increase in autoregressive decoding throughput.Fourier Compressor removes visual tokens by shrinking their spatial frequency representation. It applies a two-dimensional type-II DCT independently across feature channels, keeps a low-frequency rectangle, and applies an inverse DCT on the smaller grid. The compressor adds no learned parameters, but the surrounding VLM is trained to accommodate the altered features.Official ECCV spotlight record · Official code

    Work: Which frequencies and tasks lose evidence at a matched training and token budget?

    Exit evidence: TextVQA and video subtasks can regress despite strong average retention; TTFT is not decoding throughput.

  10. 2026

    Diverse representatives and temporal token merging

    FlashVID preserves representative video tokens and merges the unselected remainder into similarity trees. Compare token budgets, compression overhead and complete time to first token separately.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    10.01FlashVID: Efficient Video Large Language Models via Training-free Tree-based Spatiotemporal Token Merging2026 · ICLR · Peer reviewedZiyang Fan, Keyu Chen, Ruilong Xing, Yulin Li, Li Jiang, Zhuotao TianOfficial ICLR 2026 oral and full proceedings manuscript checked. Inference-time token selection/merging, not residual-error KD. Full configuration includes segmentation, budget adjustment and hybrid LLM pruning. Report encoding and compression overhead as well as LLM savings; natural-video evidence is not cross-magnification pathology validation.FlashVID compresses video tokens without training the target Video LLM. Attention-guided Diverse Token Selection keeps representative tokens, while Tree-based Spatiotemporal Merging pools redundant tokens across adjacent frames. This is token selection and merging, not teacher–student knowledge distillation.Official proceedings record · OpenReview · Official implementation

    Work: Which information survives selection or merging, and where is compression cost included?

    Exit evidence: Residual tokens are not residual-error KD; large LLM-only savings are not the same as end-to-end acceleration.

  11. 2026

    State-space discretization, rotations and update rank

    Mamba-3 separates numerical discretization, complex-state expressivity and MIMO hardware utilization. Follow each mechanism into its own quality or efficiency experiment.

    Key papers in this section

    OrderPrimary paper · authors · year · venue/statusCore idea and why to read itOfficial resources
    11.01Mamba-3: Improved Sequence Modeling using State Space Principles2026 · ICLR · Peer reviewedAakash Sunil Lahoti, Kevin Li, Berlin Chen, Caitlin Wang, Aviv Bick, Zico Kolter, Tri Dao, Albert GuOfficial ICLR 2026 oral and full proceedings manuscript checked. Three selective-SSM changes evaluated on language and synthetic sequences. Distinguish conditional discretization theory from learned gates, parameter matching from compute matching, and fixed-state decoding from information-retrieval capability. No direct pathology or natural-image evaluation.Mamba-3 changes a recurrent state-space language model along three axes: exponential-trapezoidal discretization, complex-valued state dynamics expressed through input-dependent rotations, and multi-input multi-output (MIMO) updates. The aim is better modeling and state tracking while using memory-bound decoding hardware more effectively.Official proceedings record · OpenReview · Official implementation

    Work: Which assumptions are enforced, which costs are matched, and where does a fixed state lose information?

    Exit evidence: Parameter matching is not compute matching; language and synthetic-sequence results do not establish WSI performance.

Research branches

Distilled deployment

Which online/offline transfer cost is paid once, which modules or experts are active, and which quality/latency benefit persists at serving time?

DistilBERT, a Distilled Version of BERT: Smaller, Faster, Cheaper and Lighter · MiniLM: Deep Self-Attention Distillation for Task-Agnostic Compression of Pre-Trained Transformers · MiniLLM: Knowledge Distillation of Large Language Models · DistiLLM: Towards Streamlined Distillation for Large Language Models · TAID: Temporally Adaptive Interpolated Distillation for Efficient Knowledge Transfer in Language Models · MiniPLM: Knowledge Distillation for Pre-Training Language Models · LLaVA-MoD: Making LLaVA Tiny via MoE-Knowledge Distillation

Serving and scheduling

How are prefill, decode, batching, prefix reuse, cache, placement, and admission scheduled?

FlashAttention: Fast and Memory-Efficient Exact Attention with IO-Awareness · Efficient Memory Management for Large Language Model Serving with PagedAttention · Fast Inference from Transformers via Speculative Decoding · DistServe: Disaggregating Prefill and Decoding for Goodput-Optimized Large Language Model Serving · SGLang: Efficient Execution of Structured Language Model Programs

Comparison table

Systems optimization layers
Family or stageScientific distinctionMain riskAnchors
Parallel statePartitions training computation and memory across devices.Communication and pipeline bubbles erase theoretical savings.2020 · 2021
Distilled checkpointPays teacher-transfer cost to reduce steady-state model size, activated experts, or generation cost.Fewer total or activated parameters need not improve hardware latency; tokenizer, data, and teacher-call costs can dominate.2019 · 2020 · 2024 · 2024 · 2025 · 2025 · 2025
Kernel / cache / schedulingChanges memory movement, allocation, placement, and prefix reuse without changing model weights.Speedups depend on hardware, request trace, shape, load, and software version.2022 · 2023 · 2024 · 2024
Drafting / quantizationReduces serial work or numeric cost under verification or error control.Quality drift, calibration loss, or low acceptance can erase gains.2023 · 2023 · 2024
Sparse / stateful sequence modelChanges the interaction graph or updates internal state while processing the sequence.Asymptotic savings may not survive kernel, optimizer-state, or online-update overhead.2025 · 2025 · 2026
Prune, distil, and audit causal servingMinitron recovers structured pruning with KD; GISP trains globally ranked nested subnetworks; prefix-invariance auditing tests the causal implementation rather than trusting its mask declaration.Parameter or FLOP reductions may not become latency savings, subnet ranking may drift by task, and a nominal causal mask may leave information leaks through implementation paths.2024 · 2026 · 2026
Residual distillation, bounded attention, and low-cost pretrainingConnects cross-tokenizer residual objectives, bounded-context baselines, and reproducible commodity-hardware pretraining.Ignoring teacher states, post-training, compilation, or utilization can reverse a claimed efficiency result.2026 · 2026 · 2026 · 2026
Frequency-domain visual token budgetsFourier Compressor uses fixed DCT truncation on feature grids, followed by VLM adaptation. Distinguish parameter-free compression from training-free deployment, and average retention from fine-detail fidelity.TextVQA and video subtasks can regress despite strong average retention; TTFT is not decoding throughput.2026
Diverse representatives and temporal token mergingFlashVID preserves representative video tokens and merges the unselected remainder into similarity trees. Compare token budgets, compression overhead and complete time to first token separately.Residual tokens are not residual-error KD; large LLM-only savings are not the same as end-to-end acceleration.2026
State-space discretization, rotations and update rankMamba-3 separates numerical discretization, complex-state expressivity and MIMO hardware utilization. Follow each mechanism into its own quality or efficiency experiment.Parameter matching is not compute matching; language and synthetic-sequence results do not establish WSI performance.2026

Concept lineage

Failure modes to audit

  • Reporting theoretical FLOPs instead of wall-clock distributions.
  • Comparing different output quality or context lengths.
  • Hiding warm-up, compilation, and queueing.
  • Using throughput-only results for interactive latency claims.
  • Omitting hardware, software, power, and failure recovery.

Questions for every paper

  1. What exact model and checkpoint run?
  2. Which memory terms dominate?
  3. What request distribution is measured?
  4. What quality constraint is held fixed?

31 canonical readings · 2018–2026· route reviewed through October 2, 2026.

This is the complete structured list for this chapter, ordered chronologically from earlier foundations toward current work. The explanatory ladder above highlights the shortest conceptual route; this list also includes important branches, benchmarks, and current endpoints. It is generated from the same deduplicated catalog used by the AI background registry and My Library, so a future catalog update appears here automatically.

Show all 31 readings in maintained order
  1. #202025ICLRPeer reviewedL2–L3

    LLaVA-MoD: Making LLaVA Tiny via MoE-Knowledge Distillation

    Fangxun Shu, Yue Liao, Lei Zhang, Le Zhuo, Chenning Xu, Guanghao Zhang, Haonan Shi, Long Chen, Tao Zhong, Wanggui He, Siming Fu, Haoyuan Li, Zhelun Yu, Si Liu, Hongsheng Li, and Hao Jiang

    Peer-reviewed ICLR 2025 conference paper.

    Official artifacts: Official code

    Metadata checked

  2. #242026arXivPreprintL3

    Sliding-window beats linear attention

    Alexia Jolicoeur-Martineau, Rhea Sanjay Sukthanker, Pashmina Cameron, and Emy Gervais

    arXiv v1 submitted 28 August 2026. No peer-reviewed record, code release, or model artifact was verified on 2 September 2026; it is retained for its unusually important negative baseline evidence rather than publication status.

    Metadata checked

  3. #252026arXivPreprintL3

    Puro-2B: Poor Lab's Qwen2-1.5B Trained on RTX 5090 within $5090

    Kairong Luo, Jiarui Cui, Yaorui Yin, Shengqi Chen, Yiming Yang, Linxiang Gao, Yanmohan Wang, Mingzhe Zhang, Kaiyue Wen, Kaifeng Lyu, and Wenguang Chen

    arXiv v1 submitted 27 August 2026. Catalog authors follow the current arXiv metadata; the PDF title page additionally names Chengxia Li, an unresolved source-metadata discrepancy that should be rechecked on revision. Code, data, and checkpoints were released, but no peer-reviewed record was verified.

    Official artifacts: Official training implementation · Official models and data collection

    Metadata checked

  4. #272026EMNLPAccepted · proceedings pendingL3

    ACTD: Anchor-Based Cross-Tokenizer Distillation with Residual Regularization

    Huiyi Zhang, Zijian Li, Xiaocheng Feng, Weitao Ma, Xiaoliang Yang, Yichong Huang, and Bing Qin

    The arXiv record reports acceptance to the EMNLP 2026 main conference. No final ACL Anthology proceedings record was available at the 2026-09-02 audit, so methods and results remain pinned to arXiv v1 submitted 30 August 2026.

    Official artifacts: Official implementation

    Metadata checked

  5. #282026ECCVAccepted · proceedings pendingL3

    Fourier Compressor: Frequency-Domain Visual Token Compression for Vision-Language Models

    Huanyu Wang, Jushi Kai, Haoli Bai, Lu Hou, Bo Jiang, Ziwei He, Zhouhan Lin

    ECCV 2026 spotlight verified from the official linked program event. Review uses the conference-hosted manuscript checked 2026-09-12; a separate Springer version of record was not verified. Parameter-free compression is NOT training-free: Section 5.1 and Table 2 require adaptation. The 31.2% number concerns reduced time to first token, not a measured 31.2% increase in autoregressive decoding throughput.

    Official artifacts: Official ECCV spotlight record · Official code

    Metadata checked

  6. #292026ICLRPeer reviewedL3

    FlashVID: Efficient Video Large Language Models via Training-free Tree-based Spatiotemporal Token Merging

    Ziyang Fan, Keyu Chen, Ruilong Xing, Yulin Li, Li Jiang, Zhuotao Tian

    Official ICLR 2026 oral and full proceedings manuscript checked. Inference-time token selection/merging, not residual-error KD. Full configuration includes segmentation, budget adjustment and hybrid LLM pruning. Report encoding and compression overhead as well as LLM savings; natural-video evidence is not cross-magnification pathology validation.

    Official artifacts: Official proceedings record · OpenReview · Official implementation

    Metadata checked

  7. #302026ICLRPeer reviewedL3

    Mamba-3: Improved Sequence Modeling using State Space Principles

    Aakash Sunil Lahoti, Kevin Li, Berlin Chen, Caitlin Wang, Aviv Bick, Zico Kolter, Tri Dao, Albert Gu

    Official ICLR 2026 oral and full proceedings manuscript checked. Three selective-SSM changes evaluated on language and synthetic sequences. Distinguish conditional discretization theory from learned gates, parameter matching from compute matching, and fixed-state decoding from information-retrieval capability. No direct pathology or natural-image evaluation.

    Official artifacts: Official proceedings record · OpenReview · Official implementation

    Metadata checked

  8. #312026ICLRPeer reviewedL3

    SliderQuant: Accurate Post-Training Quantization for LLMs

    Shigeng Wang, Chao Li, Yangyuxuan Kang, Jiawei Fan, Zhonghong Ou, and Anbang Yao

    Peer-reviewed ICLR 2026 poster; retain as a frontier quantization method after systems and quantization foundations.

    Official artifacts: Code

    Metadata checked