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Cerebras Deploys Trillion-Parameter AI Models

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Cerebras is deploying trillion-parameter AI models on its wafer-scale chips, addressing the challenge of memory requirements. A single Cerebras WSE-3T wafer has 44 GB of on-chip memory, while trillion-parameter models need terabytes for their weights. To overcome this, Cerebras uses a distributed approach where multiple wafers collaborate, with each wafer processing specific model layers and passing activations to the next, until the final wafer generates the output token.

Why this one

This report details how Cerebras is deploying trillion-parameter models by distributing layers across multiple wafers, unlike other approaches that might focus on single-chip scaling.

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PublishedOffset at this time: UTC+0Oct 25, 2026, 01:33 UTC

IngestedOffset at this time: UTC+0Oct 25, 2026, 03:00 UTC

Published
Oct 25, 2026, 01:33
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Oct 25, 2026, 03:00
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One of the most frequently asked questions we get is how we deploy large models on Cerebras wafer-scale chips. A single Cerebras WSE-3T wafer has 44 GB of on-chip memory, and trillion-parameter frontier models need terabytes for their weights alone.

In this post, we’ll explain how we split a large frontier model across multiple WSE-3T wafers, to run multi-trillion parameter models at 1000-2000+ tokens per second.

We’ll use the open source model Kimi K3, with ~3 trillion parameters, as an illustrative example.

By the end, you'll understand:

- How we fit the full model into on-chip memory

- How we map the model across multiple chips

- How we handle a high # of concurrent requests

Breaking it down with Kimi K3

Kimi K3 is an open source, 3T parameter model with 69 linear-attention layers and 24 dense layers.

For this illustrative example, we use:

- A 256k assumed average request size

- 4-bit weight quantization (like the Hugging Face implementation )

- An 8-bit KV cache

#1: Size of Each layer

To calculate the total number of Cerebras WSE-3T wafers we need to support Kimi K3, let’s first calculate the size of each model layer.

Kimi K3 has 3 trillion parameters. If all 3T parameters are stored at 4 bits each, the raw parameter payload is:

Dividing that payload by 93 layers then gives:

#2: Number of Wafers

Now that we know each layer needs about 16 GB, we can figure out how many layers fit on each 44 GB wafer. The answer depends on the layer type:

- Dense layers need additional room for a KV cache, because each dense (full-attention) layer stores the keys and values for every token in every active request. So, we place one dense layer per wafer and leave the remaining SRAM for its KV cache.

- Linear-attention layers do not require additional room for a KV cache. Instead of storing keys and values for every token, a linear-attention layer keeps a small, fixed-size state per request, regardless of context length. That leaves room for two linear layers per wafer (2 × 16 GB = 32 GB).

Therefore, with Kimi K3’s 69 linear layers and 24 dense layers , we get:

This gives us a total wafer count of 35 + 24 = 59 wafers.

#3: Connecting the wafers together

Source·Hacker News·cerebras.ai