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Generative AI· Qwen3.8-27B

Qwen3.8-27B VRAM: 11GB to 56GB by Quant Level

Qwen3.8-27BAlibabaOpen-Weight Models
Qwen3.8-27B VRAM: 11GB to 56GB by Quant Level

Qwen3.8-27B VRAM by quantization level

The 27B weights do not ship in one size. Quantization, which stores each weight with fewer bits, is what decides whether the model lands on a consumer card at all.

Total memory by quantization level

QuantizationMemory required
2-bit11-13 GB
3-bit13-16 GB
4-bit17-19 GB
6-bit24 GB
8-bit31 GB
BF16 (uncompressed)56 GB

Run Qwen3.8-27B locally: the 4-bit build fits a 24GB card

Unsloth puts the 4-bit build at 17-19GB and names the cards it lands on: an RTX 5080, a 4090, or a Mac with 24GB of RAM. That range is the practical target for anyone running the model on hardware they already own.

Two details in the table are easy to miss. The unit is total memory rather than VRAM alone, so a Mac's unified memory counts the same way a discrete card does. And a 16GB GPU is short even at 4-bit, which pushes it down to 3-bit or 2-bit where the quality drop starts to show in longer outputs.

View official source →
"Qwen3.8-27B 4-bit quants will work on most devices 17-19GB VRAM like RTX 5080, 4090 or a Mac with 24GB RAM." — from the Qwen3.8-27B Requirements section, where the per-level values are given as 2-bit "11-13 GB", 3-bit "13-16 GB", 4-bit "17-19 GB", 6-bit "24 GB", 8-bit "31 GB" and BF16 "56 GB", under the heading "Table: Hardware requirements (units = total memory: RAM + VRAM, or unified memory)"

Context length is billed on top of the weights

The memory table covers the weights only. Every token in the context window occupies a KV cache, the store of past tokens the model keeps while it generates, and that cache lives beside the weights rather than inside them.

This matters because the native window is 262,144 tokens. A 4-bit build that fits in 19GB does not stay at 19GB once a long document is loaded, so a 24GB card that looks comfortable on paper can run out at full context. Sizing from the quant table alone is the most common way to be surprised.

View official source →
"Context Length: 262,144 natively and extensible up to 1,000,000 tokens."

The million-token figure is a ceiling, not a default

The 1M number that travels with this release is the extended ceiling, not what the downloaded weights do out of the box. Reaching it means applying YaRN, a technique that stretches positional information to buy a longer window, and paying for the additional KV cache that comes with it.

Qwen also lists a 1M context window as a feature of the hosted version rather than of the local weights. Anyone planning capacity around a million tokens on their own hardware is planning around the wrong number.

View official source →
"Maximum context window: 262,144 (can be extended to 1M via YaRN)" — from the Recommended Settings section

What the hardware actually buys

Fitting the model on a card is one question. What the model is licensed and built to do is another, and it is where a 27B open-weight release earns its place over an API.

The weights are licensed under Apache 2.0, which allows modification, redistribution and commercial use without a separate agreement. Embedding it in an internal system, shipping it inside a product, or publishing a fine-tuned derivative are all covered.

One distinction is worth keeping straight: open weight is not open source. Qwen publishes the weights, not the training data or the full recipe, so the model cannot be reproduced from scratch. For deployment that changes nothing, but for anyone auditing provenance it changes a great deal.

View official source →
"License: apache-2.0"

Images and video are native inputs

Qwen3.8-27B reads images and video directly rather than through a separate captioning step. Qwen describes the coverage as running from STEM diagrams and documents up to hour-scale video.

For a self-hosted deployment that removes a whole component. Document work that would otherwise need an OCR stage, a layout parser and a language model can be handed to one set of weights, which is a meaningful saving when the point of running locally was to keep the stack small.

View official source →
"Vision-Language Understanding: Native support for image and video understanding, from STEM diagrams and documents to hour-scale videos."

The official FP8 build is not a consumer-GPU option

Qwen ships its own FP8 quantization, and the model card says its scores are nearly identical to the original. FP8 stores each number in eight bits, applied here at a block size of 128.

Quality-wise that is the safest reduction on offer, because the people who trained the model produced it. Size-wise it is out of reach for a single consumer card: the 8-bit row in the table is already 31GB. On hardware you own, the realistic landing point remains a community-made GGUF build around 4-bit. GGUF is the quantized file format that llama.cpp-based tools read.

View official source →
"The quantization method is fine-grained fp8 quantization with block size of 128, and its performance metrics are nearly identical to those of the original model."

Before you buy hardware for it

Two things are worth checking before a benchmark score turns into a purchase order.

The benchmark table is not measured under matched conditions

Qwen's own footnote says the comparison models were re-measured rather than quoted. Only one competitor's score is the officially reported one; the rest were run by Qwen through the Claude Code harness at a fixed temperature and context window.

Re-measuring is not misconduct, and stating it is the honest thing to do. It does mean that small gaps between vendors in that table carry less information than they appear to, because part of the difference is the harness rather than the model.

View official source →
"Except for Opus4.6 Max, which uses the officially reported score, all models are evaluated with the Claude Code harness at temp=1.0, top_p=0.95, and a 256K context window."

Serving engine and sampling settings change the result

Loading the weights is not the same as running them well. Qwen recommends dedicated serving engines for production throughput, and publishes different sampling settings for thinking and non-thinking modes.

Getting these wrong is a common reason a local build feels worse than the hosted demo. The thinking mode expects temperature 1.0 with top_p 0.95; the instruct mode expects temperature 0.7 with top_p 0.80. Leaving a client's defaults in place quietly evaluates a different configuration from the one the scores describe.

View official source →
"For production workloads or high-throughput scenarios, dedicated serving engines such as SGLang, vLLM, or TokenSpeed are recommended."

The model card that holds all of these numbers is built from tables and nested bullet lists, and copying it into a chat window flattens exactly the structure the numbers live in. Converting the page to markdown first keeps the headings and tables intact, so nothing is silently dropped when a model reads it back.

Free ToolURL to Markdown ConverterConvert any public web page URL to Markdown. Preserves headings, tables, lists, and links — perfect for LLM and RAG preprocessing, research notes, and archiving web articles.Try it now →

Qwen3.8-27B is a rare combination: a size that fits on hardware people already own, under a license that asks nothing in return. The honest constraint is memory. Pick the quantization level your card can hold, leave room for the context you actually use, and test it on your own workload before deciding — the published scores were measured on someone else's setup, and the memory table is the part that applies directly to yours.

FAQ

Q. How much VRAM does Qwen3.8-27B need?
17-19GB at 4-bit, which is the level most single-GPU setups land on. The uncompressed BF16 weights need 56GB. Unsloth publishes the figure as total memory, so unified-memory Macs count the same way as discrete VRAM.
Unsloth Documentation — Qwen3.8
Qwen3.8-27B 4-bit quants will work on most devices 17-19GB VRAM like RTX 5080, 4090 or a Mac with 24GB RAM. Unsloth Documentation — Qwen3.8
Q. Will Qwen3.8-27B fit on a 16GB GPU?
Not at 4-bit. The 4-bit build starts at 17GB, so a 16GB card has to drop to 3-bit (13-16GB) or 2-bit (11-13GB), and output quality falls with it. A 24GB card is the first size that holds 4-bit with room for context.
Unsloth Documentation — Qwen3.8
4-bit 17-19 GB Unsloth Documentation — Qwen3.8
Q. Can I use Qwen3.8-27B in a commercial product?
Yes. The weights ship under Apache 2.0, which permits modification, redistribution and commercial use without a separate agreement. Note that open weight is not the same as open source: the training data and full recipe are not published.
Hugging Face — Qwen/Qwen3.8-27B model card
License: apache-2.0 Hugging Face — Qwen/Qwen3.8-27B model card
Q. Does the 1M context window work on the downloaded weights?
No. The model card separates the two: 262,144 tokens is native, and 1,000,000 is the extended ceiling reached through YaRN. A 1M window by default is listed as a feature of the hosted version, not of the local weights.
Hugging Face — Qwen/Qwen3.8-27B model card
Context Length: 262,144 natively and extensible up to 1,000,000 tokens. Hugging Face — Qwen/Qwen3.8-27B model card

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