Pinned Tweet
vLLM has grown to 2000+ contributors scale with a diverse community of model, hardwares, and applications. I see @vllm_project on the path of becoming the world's inference engine and @inferact to accelerate AI progress. We cannot be more excited about the road ahead.
Today, we're proud to announce @inferact, a startup founded by creators and core maintainers of @vllm_project, the most popular open-source LLM inference engine. Our mission is to grow vLLM as the world's AI inference engine and accelerate AI progress by making inference cheaper and faster. The Challenge Inference is not solved. It's getting harder. Models grow larger. New architectures proliferate: mixture-of-experts, multimodal, agentic. Every breakthrough demands new infrastructure. Meanwhile, hardware fragments: more accelerators, more programming models, and more combinations to optimize. The capability gap between models and the systems that serve them is widening. Left this way, the most capable models remain bottlenecked and with full scope of their capabilities accessible only to those who can build custom infrastructure. Close the gap, and we unlock new possibilities. And the problem is growing. Inference is shifting from a fraction of compute to the majority: test-time compute, RL training loops, synthetic data. We see a future where serving AI becomes effortless. Today, deploying a frontier model at scale requires a dedicated infrastructure team. Tomorrow, it should be as simple as spinning up a serverless database. The complexity doesn't disappear; it gets absorbed into the infrastructure we're building. Why Us vLLM sits at the intersection of models and hardware: a position that took years to build. When model vendors ship new architectures, they work with us to ensure day-zero support. When hardware vendors develop new silicon, they integrate with vLLM. When teams deploy at scale, they run vLLM, from frontier labs to hyperscalers to startups serving millions of users. Today, vLLM supports 500+ model architectures, runs on 200+ accelerator types, and powers inference at global scale. This ecosystem, built with 2,000+ contributors, is our foundation. We've been stewards of this engine since its first commit. We know it inside out. We deployed it at frontier scale—in research and in production. Open Source vLLM was built in the open. That's not changing. Inferact exists to supercharge vLLM adoption. The optimizations we develop flow back to the community. We plan to push vLLM's performance further, deepen support for emerging model architectures, and expand coverage across frontier hardware. The AI industry needs inference infrastructure that isn't locked behind proprietary walls. Join Us Through the open source community, we are fortunate to work with some of the best people we know. For @inferact, we're hiring engineers and researchers to work at the frontier of inference, where models meet hardware at scale. Come build with us. We're fortunate to be supported by investors who share our vision, including @a16z and @lightspeedvp who led our $150M seed, as well as @sequoia, @AltimeterCap, @Redpoint, @ZhenFund, The House Fund, @strikervp, @LaudeVentures, and @databricks. - @woosuk_k, @simon_mo_, @KaichaoYou, @rogerw0108, @istoica05 and the rest of the founding team
12
9
105
24,376
ClusterMAX 3.0: The Industry Standard GPU Cloud Rating System Returns In gory detail: reliability, performance, support, pricing —and, of course, security— in our most thorough analysis of GPU cloud providers globally semianalysis.substack.com/p/…
1
20
2,088
Simon Mo retweeted
As coding agents get more powerful, it’s time to take engineering to the next level. So proud of the @inferact team for pushing the frontier of inference with our TPU megakernel. We are hiring!
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
3
9
95
6,849
Simon Mo retweeted
When I first learned about the results, I was very surprised. Megakernels have been hard on GPUs, barely beating CUDAgraph+PDL. Then @woosuk_k explained to me. TPU only has 1-2 core compute units, instead of hundreds SMs on NVIDIA GPUs, making megakernels very natural (synchronization across SMs is what kills megakernels on NVIDIA) Then I wonder why no one has done it earlier. Perhaps cuz they don't have the cracked @woosuk_k and @inferact team 🫡
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
8
19
268
14,692
Simon Mo retweeted
The @inferact team open sourced a TPU megakernel for Kimi K3 achieving 709 tokens/s, against 450 tokens/s on GB200. All 92 of K3's MoE layers run in a single Pallas kernel, with weight prefetching that reaches across layer boundaries so transfers for one layer overlap with computation in the previous one. Shoutout to the team! Writeup and repo link in the thread.
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
9
16
186
14,634
Simon Mo retweeted
we spent last month trying to write a megakernel for a much smaller model. people don’t realize how hard this is. amazing work from inferact!
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
3
1
12
1,127
Simon Mo retweeted
TPUs actually go Brrrrr 🚀
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
1
4
360
Simon Mo retweeted
Can we buy more TPUs plz
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
1
1
4
445
Simon Mo retweeted
Replying to @SemiAnalysis_
Especially impressive considering TPU has slightly worse hardware specs (also cheaper) than GPU.
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
1
2
11
1,690
Simon Mo retweeted
Simple idea. Great Engineering
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
1
20
1,608
Simon Mo retweeted
I did not see TPUs beating GPUs on decode any time soon, until @woosuk_k and the cracked team pulled it off with a single Pallas kernel running all of Kimi K3 at 709 tok/s 🤯 First TPU inference megakernel I know of, and it is open source today! The numbers speak for themselves, and the blog is definitely worth your time 🚀
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
12
14
238
54,772
Simon Mo retweeted
ALERT ALERT ALERT 🚨 🚨 🚨 VLLM MAINTAINERS HAVE JUST SHOWN THAT TPUv7 CAN GET 700 tok/s/user,  56% BETTER PERFORMANCE THAN NVIDIA GB200 NVL72 THROUGH MEGAKERNEL OPTIMIZATION ON KIMI K3. As we said awhile ago, the TPU externalization of software is full steam ahead. This is ultra important to follow the progress of this.
65
112
1,580
288,336
Megakernels on TPU, open sourced today! Great work by the @inferact team bringing open source inference to frontier hardware at speed of light 🚀
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
2
4
98
8,509
Simon Mo retweeted
Our first TPU megakernel for Kimi K3 reaches 709 tokens/s on low-concurrency decode, against 450 tokens/s for our GB200 baseline, both with DSpark speculative decoding. To our knowledge, this is the first TPU inference megakernel. The whole model runs in a single Pallas kernel, and without spec decoding it is roughly 1.4 to 2x the GB200 baseline at batch sizes 1 through 8. We are open sourcing it today. 1/2
22
92
846
233,415
Simon Mo retweeted
DiffusionGemma-Jev now runs on vLLM 🚀 Ask yes/no, multiple-choice, or scored questions and get confidence with every answer. vLLM seeds a canvas with the response template, leaves only the answer slots noisy, then reads a probability distribution from every slot in a single denoising step. Huge thanks to @mmastrac for driving this upstream! 🙏 github.com/vllm-project/vllm…
Deploying DiffusionGemma-Jev (djev) just got a lot easier. You can now spin up a Jev API-compatible endpoint on Google Cloud Run using a single command. Performance is solid: ~35-60 ms for single step latency and batch@32 is ~100-123 requests/sec. It's a straightforward way to experiment without needing your own GPU. Runs at roughly $3/hr and drops to $0 when idle. Get the code and instructions here: github.com/taeold/djev-run
24
135
1,274
104,864
Simon Mo retweeted
762 commits. 315 contributors. 104 first-timers. vLLM v0.30.0 is live. 🎉 Highlights: 🤖 Hybrid-attention hot paths: Kimi K3 streamlines KDA, AttnRes, and MLA; DeepSeek-V4.1-Flash adds MXFP8 KV and async Engram; Qwen3.8-Flash-Next fuses QSA/PLE and cuts sparse-GQA overhead 🗄️ HiSparse adds a host tier beneath sparse-MLA decode; under GPU pressure, only top-k misses return to a per-request hot buffer 🛠️ Model Runner V2 brings EAGLE3-style drafts to pipeline parallelism and extends adaptive verification to every draft-model speculator through online acceptance estimation (#50514, #52228) 🖋️ Dual-key Gumbel-max watermark generation and detection, with per-request opt-out and speculative-decoding support 🆕 New models include GLM-5.3-Flash, K2-Horizon, Cohere Compass, and Bailing V3 VL ⚡ Fast Start keeps post-quantized, TP-sharded weights in a per-GPU daemon; restarts map them over CUDA IPC with --load-format ipc_cache Thread 👇
18
31
238
18,393
Simon Mo retweeted
Excited to see @peano_ai run full-parameter RL for @XiaomiMiMo 310B MiMo-V2.6 on TPUs, across 1,000+ TPUs. 🚀🚀 vLLM drives the rollouts, bitwise-matched with the trainer in validation. All 310B params move across the ICI fabric in under 2s. 🔗 peano-labs.ai/blog/scaling-m…
We enable full-parameter RL on TPUs: MiMo-V2.6 at 310B, plus other stable training runs of 1,000+ steps across 1,000+ TPUs. With JAX, scaling up is a config change, not a rewrite. We built on that with optimized vLLM inference for faster rollouts and full bitwise trainer–sampler agreement in validation. Trainer and sampler share one TPU ICI fabric. All 310B MiMo-V2.6 parameters transfer in <2 seconds.
11
12
105
11,374
Simon Mo retweeted
@googlecloud and Inferact are announcing today a partnership to make TPU a first-class citizen in @vllm_project. This partnership puts both teams on one engineering roadmap to bring TPU to the broader open model ecosystem, optimizing vLLM as the agentic production serving engine for TPU: • Production serving features and optimized kernels • A native PyTorch path via TorchTPU • Moving towards day-0 support for frontier model releases We're also launching a community program: shared TPU capacity for open-source contributors, plus dedicated review and design help from the core vLLM maintainers at Inferact. Everything this collaboration produces is open source. Read the full announcement: inferact.ai/news/google-tpu-…
10
38
190
104,380
The first YOCO (you only look once) model for agentic use with shared kv cache and efficiency. vLLM is the go to production engine for agentic workload!
🐳 DeepSeek-V4.1-Flash is out, and vLLM serves it from day 0, verified on NVIDIA and AMD GPUs! 🎉 552B MoE backbone, native vision, 1M context. Built for agents: 8B active while it reads your prompt, 16B while it writes. If you already run DeepSeek-V4 on vLLM, most of this stack will feel familiar: the hyper-connections, the sliding-window plus compressed sparse attention, DSpark drafting, MXFP4 experts. vLLM has carried all of it since V4 landed. Two things are new, and both are worth a look: ✨ Engram: a quarter of the checkpoint is n-gram memory the model looks up instead of computes. 197B parameters of it. ✨ Only four layers write compressed KV now. The rest of the model shares it. Spin it up 👇 🔗 recipes.vllm.ai/deepseek-ai/…
5
6
59
4,465
Simon Mo retweeted
Sparse MLA only attends to the top-K tokens, so the rest of the KV need not live on the GPU. Hybrid HiSparse in vLLM builds on that, and a request keeps decoding after its KV stops fitting in HBM. It keeps KV on the GPU while there is room. Under pressure a request releases its coldest pages to host memory, keeps a small hot buffer of what the indexer asks for, and keeps decoding instead of being preempted. 📊 Demonstrated on GLM 5.3, one 8× H200 node, full 1M context. Same host memory, configured concurrency 32: KV offloading kept 5-6 requests running. Hybrid HiSparse kept 19-25. 🔹 Hot pages are ordinary KV blocks from the same pool (Hybrid Memory Allocator) 🔹 One fused kernel resolves resident, hot and missing rows, CUDA-graph capturable 🔹 Prefix caching, OffloadingConnector, P/D imports and MTP keep working Built by @RedHat_AI and @PrimeIntellect with the vLLM community. Planned for v0.30; pinned commit, flags and calculator are in the post👇 🔗 vllm.ai/blog/2026-09-08-glm5…
9
28
166
29,110