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Command R 35B KV-Cache Calculator

Per-token and total key-value cache memory for Command R 35B across context length, batch size and cache precision.

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Per token (KB)
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Per sequence (GB)
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Total cache (GB)

Command R 35B: ~160.0 KB per token at FP16. Cohere's Command R 35B is tuned for RAG and tool use at 128K context; with 8 KV heads on a wide 8192 hidden size, cache planning dominates deployment decisions.

Formula

cache/token = 2(K,V) ร— layers ร— kv_heads ร— head_dim ร— bytes = 2 ร— 40 ร— 8 ร— 128 ร— bytes
References: Command R 35B config.json (Hugging Face); Kwon et al. (2023), PagedAttention / vLLM

Disclaimer: This tool is for general informational and estimation purposes only and is not professional financial, tax, accounting or legal advice. All figures are estimates โ€” verify with a qualified professional before making decisions. Read the full disclaimer.

About Command R 35B KV-Cache Calculator

The KV cache is the hidden memory cost of serving Command R 35B: every generated or prompted token stores its attention keys and values for reuse, and at long contexts this cache can rival the model weights themselves. This calculator uses Command R 35B's exact attention geometry (8 KV heads ร— 128-dim heads ร— 40 layers) to give per-token, per-sequence and whole-batch cache sizes at FP16, FP8 and INT4 precision. Use it to size batch limits for your GPU or to see what a 128K-context request really costs.

How to use Command R 35B KV-Cache Calculator

  1. 1Enter your values into Command R 35B KV-Cache Calculator โ€” sensible, domain-typical defaults are pre-filled so you see a real result immediately.
  2. 2The result recomputes live using the formula shown on the page; there is no button to press.
  3. 3Adjust any input to compare scenarios, then read the worked example to see the substituted numbers.

Why use Command R 35B KV-Cache Calculator?

  • โœ“Computes Command R 35B KV-Cache instantly in your browser โ€” no sign-up, no upload, no server round-trip.
  • โœ“100% free and unlimited, with the exact formula shown: cache/token = 2(K,V) ร— layers ร— kv_heads ร— head_dim ร— bytes = 2 ร— 40 ร— 8 ร— 128 ร— bytes.
  • โœ“Runs entirely client-side, so every value you enter stays private on your device.
  • โœ“Live recompute as you type, with a worked example and authoritative references for trust.

Frequently asked questions

What makes Command R's memory profile RAG-friendly?+

RAG stuffs long retrieved passages into the prompt, so cache cost per token matters more than weight size. With GQA (8 KV heads ร— 128 head_dim), a 64K-token RAG context costs ~5.2 GB at FP16 โ€” manageable next to 70 GB of FP16 weights.

Single-GPU options for Command R 35B?+

FP16 weights (~70 GB) need an 80 GB card; INT8 (~35 GB) fits a 48 GB A6000/L40S with cache headroom; 4-bit (~18 GB) runs on a 24 GB card for short-to-medium contexts. Long-context RAG pushes you to 48 GB+.

Why does the KV cache matter more than weights for serving throughput?+

Weights are paid once per GPU; cache is paid per concurrent request and per token of context. Batch size โ€” and therefore throughput โ€” is capped by how many sequence caches fit in the VRAM left after weights, which is exactly what this tool computes.

What does paged attention change?+

PagedAttention (vLLM) allocates the cache in fixed-size blocks on demand instead of reserving the full context up front, eliminating fragmentation and letting you overcommit. The per-token cost shown here is unchanged โ€” you just stop paying for unused reservation.

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