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Groq vs Cerebras - Which Is Fastest LLM Inference in 2026

Fastest LLM

If you are building a real-time AI application in 2026 — voice assistant, live chat, agentic workflow, instant code completion — the speed of your inference provider is not a nice-to-have. It is a product decision.

GPU-based inference has a hard ceiling. The memory bandwidth bottleneck limits how fast tokens can be generated regardless of how many GPUs you throw at the problem. Groq and Cerebras both built purpose-designed silicon to break through that ceiling — and both have delivered numbers that make standard GPU inference look like dial-up internet.

According to verified data tracked on InferenceBench, which monitors 297 AI models across 60 GPUs and 19 providers, both Groq and Cerebras are available as active inference providers. Here is the full comparison.

TL;DR

Groq's LPU delivers approximately 1,200 tokens per second with sub-100ms time to first token on supported models. Cerebras hits over 2,600 tokens per second on Llama 4 Scout — independently verified as 19x faster than the fastest GPU solution. For raw speed, Cerebras leads. For model availability, API maturity, and developer ecosystem, Groq leads. Both are dramatically faster than standard GPU inference, and both are tracked as active providers on InferenceBench.

Why standard GPU inference is not fast enough

Most AI inference in 2026 still runs on NVIDIA GPUs — H100s, A100s, L40S clusters. They are excellent for training and for many inference workloads. For real-time applications, they have a structural problem.

LLM generation is limited by how fast you can move model weights from memory to compute for each token. Groq and Cerebras both achieve faster LLM inference than NVIDIA GPUs by addressing this memory bandwidth bottleneck.

This is not an optimization problem. It is an architectural one. Sequential token generation — the way every autoregressive LLM works — is fundamentally memory-bandwidth-bound, not compute-bound. GPUs are optimized for parallel matrix operations, not sequential memory access. Groq and Cerebras built chips for the actual workload.

The hardware — how they are different

Groq — the Language Processing Unit (LPU)

Groq's LPU is a custom ASIC designed specifically for deterministic, high-throughput AI inference. Unlike GPUs which handle many tasks in parallel, the LPU is architected for the sequential nature of autoregressive token generation.

Groq's LPU delivers 1,200 tokens per second with sub-100ms time to first token, fast enough that the LLM step matches human reaction speed.

On real-world benchmarks: Groq's LPU hardware delivers Llama 3.1 70B at approximately 330 tokens per second and Llama 3.1 8B at over 750 tokens per second.

Cerebras — the Wafer Scale Engine (WSE-3)

Cerebras takes a different architectural approach. Rather than a chip, WSE-3 is an entire wafer of silicon — the largest chip ever built for AI.

Cerebras's WSE-3 chip contains 4 trillion transistors and 900,000 cores. With speculative decoding, it achieves up to 4,000 tokens per second using a 3B-parameter draft model verified against a 70B-parameter model, giving users the speed of the smaller model with the quality of the larger one.

On Llama 4 Scout specifically: Cerebras achieves over 2,600 tokens per second on Llama 4 Scout — 19x faster than the fastest GPU solutions as verified by Artificial Analysis, a third-party AI benchmarking service.

At 1,800 tokens per second, Cerebras Inference is 2.4x faster than Groq on Llama 3.1 8B. For Llama 3.1 70B, Cerebras is the only platform to enable instant responses at a blistering 450 tokens per second.

Speed comparison — the numbers

model benchmarks

Groq's LPU delivers 476 tokens per second on GPT-OSS-120B. Cerebras reports 3,000 tokens per second on the same model. Both numbers are real, independently verified, and roughly 10 to 20 times faster than NVIDIA GPU inference on equivalent hardware.

The raw speed winner is Cerebras — by a significant margin on most models. But speed is not the only factor that determines which provider is right for your workload.

Model availability — where they differ

Speed means nothing if the provider does not serve the model you need.

Groq model availability: Groq serves a focused selection of open-weight models optimized for its LPU architecture — primarily the Llama family, Mistral variants, and Gemma models. Groq gives 30K tokens per minute with stricter daily caps. The model catalog is deliberately curated for LPU compatibility.

Cerebras model availability: Cerebras focuses primarily on Llama family models and has made Llama 4 Scout its flagship speed benchmark. Cerebras gives 1M tokens per day with longer daily runway. The model selection is narrower than Groq's but the throughput on supported models is unmatched.

For both providers, model availability is more limited than general GPU inference platforms like Together AI or Fireworks AI, which serve hundreds of models. The market divides into two camps: general-purpose providers focus on model quality, while specialized inference providers like Groq and Cerebras focus on speed and cost for open-weight models.

Pricing — what you actually pay

Neither Groq nor Cerebras publishes the same kind of detailed per-token pricing as general API providers for every model. Both operate primarily on per-token pricing for API access.

Free tier comparison: Groq gives 30K tokens per minute with stricter daily caps. Cerebras gives 1M tokens per day with longer daily runway. Groq is faster per token. Cerebras is more generous in volume.

For current verified pricing across both providers, check the InferenceBench leaderboard — pricing data is refreshed daily from provider APIs and flagged when more than 7 days stale.

Developer ecosystem and API maturity

Raw speed is one dimension. The developer experience around that speed matters for production deployments.

Groq: Groq has a more established developer ecosystem and published customer case studies. The GroqCloud API is well-documented, has broad SDK support, and is integrated into several developer tools and frameworks. For teams that need to move fast and find community resources, Groq's ecosystem is the more mature option in 2026.

Cerebras: Cerebras has a partnership with OpenAI for 750MW of wafer-scale AI systems for 2026-2028 deployment, which signals long-term infrastructure commitment. The API is straightforward but the developer community and third-party integrations are less extensive than Groq's at this stage.

Both providers score evenly when it comes to ease of use, data privacy, and ecosystem support.

Which use cases each provider wins

Choose Groq when:

Real-time voice and chat applications. For most voice AI applications, either provider makes the LLM step fast enough that it is no longer the bottleneck. The practical difference between sub-100ms TTFT and 80–150ms TTFT is measurable but unlikely to be perceptible to end users. Groq's mature ecosystem and broader model selection make it the lower-friction choice for voice and chat.

Broader model selection is required. If your application needs models beyond the Llama family — Mistral variants, Gemma, or other open-weight models — Groq's catalog is wider.

Developer tooling and community support matters. Groq's more established ecosystem means more tutorials, more third-party integrations, and more community resources for debugging and optimization.

Choose Cerebras when:

Maximum throughput is the primary requirement. For batch processing, agentic workflows, and applications where raw token generation speed determines product quality, Cerebras's 2,600+ tokens per second on Llama 4 Scout is unmatched by any provider in 2026.

Llama 4 Scout is your model. Cerebras holds the speed record for Llama 4 Scout at 2,600+ tokens per second — 19x faster than GPU-based alternatives. If Scout is your production model, Cerebras is the clear infrastructure choice.

Long daily token volume matters more than per-minute rate. Cerebras's 1M tokens per day free tier is more generous for sustained daily usage than Groq's per-minute rate limits.

The practical recommendation:

Use Cerebras for latency-critical paths. Use DeepInfra or general GPU providers for background work. Many production apps use Groq as primary with frontier models as fallback.

The smartest production architecture in 2026 routes by use case: Groq or Cerebras for speed-critical paths, general GPU inference providers for volume workloads, and frontier API providers (OpenAI, Anthropic) for quality-critical tasks where speed is secondary.

The bigger picture — inference is the growth market

In 2023, inference accounted for roughly one-third of all AI compute. By 2025, it had grown to half. Analysts project that by 2026, inference will represent approximately two-thirds of total AI compute spending — a reversal driven by the explosion of production AI deployments.

This shift is why specialized inference hardware matters. As inference becomes the dominant AI compute workload, the efficiency gap between purpose-built silicon and general GPU infrastructure becomes a significant competitive advantage.

Both Groq and Cerebras are building for this market. Both are tracked as active providers on InferenceBench, with daily availability probes and verified pricing data.

The bottom line

For raw inference speed in 2026, Cerebras leads — 2,600+ tokens per second on Llama 4 Scout, independently verified at 19x faster than GPU inference. For model availability, API maturity, and developer ecosystem, Groq leads.

The right choice depends on your primary constraint. If you are building real-time voice or agentic applications where token generation speed determines product quality, test both on your actual workload before committing. If you need the broadest model selection at high speed, Groq is the lower-friction starting point. If you need the absolute fastest throughput on Llama 4 Scout, Cerebras is the only option that delivers it.

Both providers are available to test through connected accounts on the InferenceBench Playground.
Compare Groq and Cerebras on the InferenceBench Leaderboard
Test models from both providers in the Playground

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