Carbon 8B — Hardware Requirements & GPU Compatibility
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Carbon 8B is a 8.3B-parameter open language model from HuggingFaceBio. It supports a context window of up to 32,768 tokens. At BF16 it needs about 17.08 GB of VRAM — see which GPUs and Macs can run it below.
2.4K downloads
43 likesSpecifications
- Publisher
- HuggingFaceBio
- Parameters
- 8.3B
- Architecture
- LlamaForCausalLM
- Context Length
- 32,768 tokens
- Vocabulary Size
- 155,776
- Release Date
- 2026-05-20
- License
- Apache 2.0
Get Started
HuggingFace
How Much VRAM Does Carbon 8B Need?
Select a quantization to see compatible GPUs below.
| Quantization | Bits | VRAM | + Context | File Size | Quality |
|---|---|---|---|---|---|
| BF16 | 16.00 | 17.1 GB | 21.1 GB | 16.51 GB | Brain floating point 16 — preferred for training |
Which GPUs Can Run Carbon 8B?
BF16 · 17.1 GBCarbon 8B (BF16) requires 17.1 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 23+ GB is recommended. Using the full 33K context window can add up to 4.0 GB, bringing total usage to 21.1 GB. 6 GPUs can run it, including NVIDIA GeForce RTX 5090, NVIDIA GeForce RTX 3090 Ti.
Runs great
— Plenty of headroom
Which Devices Can Run Carbon 8B?
BF16 · 17.1 GB21 devices with unified memory can run Carbon 8B, including NVIDIA DGX H100, NVIDIA DGX A100 640GB, Mac Mini M4 Pro (24 GB).
Runs great
— Plenty of headroomRelated Models
Frequently Asked Questions
- How much VRAM does Carbon 8B need?
Carbon 8B requires 17.1 GB of VRAM at BF16. Full 33K context adds up to 4.0 GB (21.1 GB total).
VRAM = Weights + KV Cache + Overhead
Weights = 8.3B × 16 bits ÷ 8 = 16.5 GB
KV Cache + Overhead ≈ 0.6 GB (at 2K context + ~0.3 GB framework)
KV Cache + Overhead ≈ 4.6 GB (at full 33K context)
VRAM usage by quantization
BF1617.1 GBBF16 + full context21.1 GB- Can I run Carbon 8B on a Mac?
Carbon 8B requires at least 17.1 GB at BF16, which exceeds the unified memory of most consumer Macs. You would need a Mac Studio or Mac Pro with a high-memory configuration.
- Can I run Carbon 8B locally?
Yes — Carbon 8B can run locally on consumer hardware. At BF16 quantization it needs 17.1 GB of VRAM. Popular tools include Ollama, LM Studio, and llama.cpp.
- How fast is Carbon 8B?
At BF16, Carbon 8B can reach ~171 tok/s on AMD Instinct MI300X. On NVIDIA GeForce RTX 4090: ~38 tok/s. Speed depends mainly on GPU memory bandwidth. Real-world results typically within ±20%.
tok/s = (bandwidth GB/s ÷ model GB) × efficiency
Example: AMD Instinct MI300X → 5300 ÷ 17.1 × 0.55 = ~171 tok/s
Estimated speed at BF16 (17.1 GB)
~171 tok/s~38 tok/s~128 tok/s~106 tok/sReal-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.
- What's the download size of Carbon 8B?
At BF16, the download is about 16.51 GB.
- Which GPUs can run Carbon 8B?
6 consumer GPUs can run Carbon 8B at BF16 (17.1 GB). Top options include NVIDIA GeForce RTX 5090, AMD Radeon RX 7900 XT, AMD Radeon RX 7900 XTX. 1 GPU have plenty of headroom for comfortable inference.
- Which devices can run Carbon 8B?
21 devices with unified memory can run Carbon 8B at BF16 (17.1 GB), including Mac Mini M4 (32 GB), Mac Mini M4 Pro (24 GB), Mac Mini M4 Pro (48 GB), Mac Pro M2 Ultra (192 GB). Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.