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KTransformers

A Flexible Framework for Experiencing Cutting-edge LLM Inference/Fine-tune Optimizations

🎯 Overview | 🚀 Inference | 🎓 SFT | 🔥 Citation | 🚀 Roadmap(2026Q2)

🎯 Overview

KTransformers is a research project focused on efficient inference and fine-tuning of large language models through CPU-GPU heterogeneous computing. The project now exposes two user-facing capabilities from the kt-kernel source tree: Inference and SFT.

🔥 Updates

  • Aug 26, 2026: Added native support for GLM-5.3-flash, bringing 1M-token context and multimodal input to consumer GPUs. (Tutorial)
  • Aug 25, 2026: Uploaded a new easy-to-use KTransformers × LlamaFactory MoE Fine-Tuning Cookbook, covering hardware checks, installation, BF16/FP8/INT8 recipes, LoRA and full fine-tuning, resource planning, and troubleshooting.
  • Aug 17, 2026: LoRA fine-tuning now supports compatible AVX512 x86 CPUs, including AMD servers, without requiring AMX. (v0.7.0 Release Notes)
  • Aug 5, 2026: Introduced native block-FP8 LoRA fine-tuning, loading FP8 routed-expert weights directly from the checkpoint without materializing a complete BF16 copy. (PR #2141)
  • July 23, 2026: Added end-to-end BF16 full-parameter fine-tuning for MoE models, including complete checkpoint saving. (PR #2094)
  • June 21, 2026: MiniMax-M3 Day0 Support! (Tutorial)
  • June 17, 2026: GLM-5.2 Day0 Support! (Tutorial)
  • May 6, 2026: KTransformers at GOSIM Paris 2026 — "Agentic AI on Edge" track. We'll present KT's inference performance on consumer hardware.
  • May 02, 2026: DeepSeek-V4-Flash Support! (Tutorial)
  • Apr 30, 2026: KTransformers v0.6.1 refreshes kt-kernel inference and SFT docs with separate Inference and SFT Quick Start entry points.
  • Mar 26, 2026: Support AVX2-only CPU backend for KT-Kernel inference. (Tutorial)
  • Feb 13, 2026: MiniMax-M2.5 Day0 Support! (Tutorial)
  • Feb 12, 2026: GLM-5 Day0 Support! (Tutorial)
  • Jan 27, 2026: Kimi-K2.5 Day0 Support! (Tutorial) (SFT Tutorial)
  • Jan 22, 2026: Support CPU-GPU Expert Scheduling, Native BF16 and FP8 per channel Precision and AutoDL unified fine-tuning and inference
  • Dec 24, 2025: Support Native MiniMax-M2.1 inference. (Tutorial)
  • Dec 22, 2025: Support RL-DPO fine-tuning with LLaMA-Factory. (Tutorial)
  • Dec 5, 2025: Support Native Kimi-K2-Thinking inference (Tutorial)
  • Nov 6, 2025: Support Kimi-K2-Thinking inference (Tutorial) and fine-tune (Tutorial)
  • Nov 4, 2025: KTransformers Fine-Tuning × LLaMA-Factory Integration. (Tutorial)
  • Oct 27, 2025: Support Ascend NPU. (Tutorial)
  • Oct 10, 2025: Integrating into SGLang. (Roadmap, Blog)
  • Sept 11, 2025: Support Qwen3-Next. (Tutorial)
  • Sept 05, 2025: Support Kimi-K2-0905. (Tutorial)
  • July 26, 2025: Support SmallThinker and GLM4-MoE. (Tutorial)
  • July 11, 2025: Support Kimi-K2. (Tutorial)
  • June 30, 2025: Support 3-layer (GPU-CPU-Disk) prefix cache reuse.
  • May 14, 2025: Support Intel Arc GPU (Tutorial).
  • Apr 29, 2025: Support AMX-Int8、 AMX-BF16 and Qwen3MoE (Tutorial)
  • Apr 9, 2025: Experimental support for LLaMA 4 models (Tutorial).
  • Apr 2, 2025: Support Multi-concurrency. (Tutorial).
  • Mar 15, 2025: Support ROCm on AMD GPU (Tutorial).
  • Mar 5, 2025: Support unsloth 1.58/2.51 bits weights and IQ1_S/FP8 hybrid weights. Support 139K Longer Context for DeepSeek-V3 and R1 in 24GB VRAM.
  • Feb 25, 2025: Support FP8 GPU kernel for DeepSeek-V3 and R1; Longer Context.
  • Feb 15, 2025: Longer Context (from 4K to 8K for 24GB VRAM) & Slightly Faster Speed (+15%, up to 16 Tokens/s), update docs and online books.
  • Feb 10, 2025: Support Deepseek-R1 and V3 on single (24GB VRAM)/multi gpu and 382G DRAM, up to 3~28x speedup. For detailed show case and reproduction tutorial, see here.
  • Aug 28, 2024: Decrease DeepseekV2's required VRAM from 21G to 11G.
  • Aug 15, 2024: Update detailed tutorial for injection and multi-GPU.
  • Aug 14, 2024: Support llamfile as linear backend.
  • Aug 12, 2024: Support multiple GPU; Support new model: mixtral 8*7B and 8*22B; Support q2k, q3k, q5k dequant on gpu.
  • Aug 9, 2024: Support windows native.

📦 Capabilities

🚀 Inference - High-Performance kt-kernel Serving

CPU-optimized kernel operations for heterogeneous LLM inference.

image

Key Features:

  • AMX/AVX Acceleration: Intel AMX and AVX512/AVX2 optimized kernels for INT4/INT8 quantized inference
  • MoE Optimization: Efficient Mixture-of-Experts inference with NUMA-aware memory management
  • Quantization Support: CPU-side INT4/INT8 quantized weights, GPU-side GPTQ support
  • Easy Integration: Clean Python API for SGLang and other frameworks

Quick Start:

cd kt-kernel
pip install .

Use Cases:

  • CPU-GPU hybrid inference for large MoE models
  • Integration with SGLang for production serving
  • Heterogeneous expert placement (hot experts on GPU, cold experts on CPU)

Performance Examples:

Model Hardware Configuration Total Throughput Output Throughput
DeepSeek-R1-0528 (FP8) 8×L20 GPU + Xeon Gold 6454S 227.85 tokens/s 87.58 tokens/s (8-way concurrency)

👉 Full Documentation →


🎓 SFT - Fine-Tuning with LlamaFactory

KTransformers × LlamaFactory integration for ultra-large MoE model fine-tuning. The new Cookbook provides an easy-to-use path from hardware checks and installation to BF16/FP8/INT8 configuration, LoRA/full training, resource planning, and troubleshooting.

LlamaFactory and KTransformers MoE fine-tuning architecture

Key Features:

  • Multi-Backend Support: CPU/GPU hybrid fine-tuning with INT8/INT4 quantization
  • Ultra-Large MoE Support: Fine-tune models like DeepSeek-V3/R1 on limited GPU memory
  • Faster than ZeRO-Offload: 6-12x training speedup in benchmarked MoE SFT workloads
  • Lower CPU Memory: About half the CPU memory of the previous KT SFT path in the benchmarked setup
  • LlamaFactory Integration: Seamless integration with the popular fine-tuning framework
Model GPU Memory Training Speed Hardware
DeepSeek-V3 ~80GB total 3.7 it/s 4x RTX 4090
DeepSeek-R1 ~80GB total 3.7 it/s 4x RTX 4090
Qwen3-30B-A3B ~24GB total 8+ it/s 1x RTX 4090

Quick Start:

cd /path/to/LLaMA-Factory
python -m pip install -e .
python -m pip install "ktransformers[sft]==0.7.0"
python -m pip install "sglang-kt==0.7.0"
CUDA_VISIBLE_DEVICES=0,1,2,3 accelerate launch \
  --config_file examples/ktransformers/accelerate/fsdp2_kt_int8.yaml \
  src/train.py \
  examples/ktransformers/train_lora/qwen3_5moe_lora_sft_kt.yaml

👉 Easy-to-Use Fine-Tuning Cookbook → 👉 Quick Start → 👉 Full Documentation →


🔥 Citation

If you use KTransformers in your research, please cite our paper:

@inproceedings{10.1145/3731569.3764843,
  title = {KTransformers: Unleashing the Full Potential of CPU/GPU Hybrid Inference for MoE Models},
  author = {Chen, Hongtao and Xie, Weiyu and Zhang, Boxin and Tang, Jingqi and Wang, Jiahao and Dong, Jianwei and Chen, Shaoyuan and Yuan, Ziwei and Lin, Chen and Qiu, Chengyu and Zhu, Yuening and Ou, Qingliang and Liao, Jiaqi and Chen, Xianglin and Ai, Zhiyuan and Wu, Yongwei and Zhang, Mingxing},
  booktitle = {Proceedings of the ACM SIGOPS 31st Symposium on Operating Systems Principles},
  year = {2025}
}

👥 Contributors & Team

Developed and maintained by:

We welcome contributions! Please feel free to submit issues and pull requests.

💬 Community & Support

📦 KT original Code

The original integrated KTransformers framework has been archived to the archive/ directory for reference. The project now organizes the two capabilities above from the kt-kernel source tree for clearer documentation and maintenance.

For the original documentation with full quick-start guides and examples, see:

Release files for ktransformers 0.7.0.post1

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for ktransformers 0.7.0.post1
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