Pantheon Reasoning 27B — Hardware Requirements & GPU Compatibility
ChatRoleplayReasoning
Pantheon Reasoning 27B is a 27.8B-parameter open language model from Gryphe. It supports a context window of up to 262,144 tokens. At Q4_K_M it needs about 17.42 GB of VRAM — see which GPUs and Macs can run it below.
415 downloads
22 likesSpecifications
- Publisher
- Gryphe
- Parameters
- 27.8B
- Architecture
- Qwen3_5ForConditionalGeneration
- Context Length
- 262,144 tokens
- Vocabulary Size
- 248,320
- Release Date
- 2026-05-30
- License
- Apache 2.0
Get Started
HuggingFace
How Much VRAM Does Pantheon Reasoning 27B Need?
Select a quantization to see compatible GPUs below.
| Quantization | Bits | VRAM | + Context | File Size | Quality |
|---|---|---|---|---|---|
| Q2_K | 3.40 | 12.6 GB | 69.4 GB | 11.81 GB | 2-bit quantization with K-quant improvements |
| Q3_K_S | 3.50 | 12.9 GB | 69.7 GB | 12.15 GB | 3-bit small quantization |
| Q3_K_M | 3.90 | 14.3 GB | 71.1 GB | 13.54 GB | 3-bit medium quantization |
| Q4_0 | 4.00 | 14.6 GB | 71.5 GB | 13.89 GB | 4-bit legacy quantization |
| Q4_K_M | 4.80 | 17.4 GB | 74.2 GB | 16.67 GB | 4-bit medium quantization — most popular sweet spot |
| Q5_K_M | 5.70 | 20.5 GB | 77.4 GB | 19.79 GB | 5-bit medium quantization — good quality/size tradeoff |
| Q6_K | 6.60 | 23.7 GB | 80.5 GB | 22.92 GB | 6-bit quantization, very good quality |
| Q8_0 | 8.00 | 28.5 GB | 85.3 GB | 27.78 GB | 8-bit quantization, near-lossless |
Which GPUs Can Run Pantheon Reasoning 27B?
Q4_K_M · 17.4 GBPantheon Reasoning 27B (Q4_K_M) requires 17.4 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 262K context window can add up to 56.8 GB, bringing total usage to 74.2 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 Pantheon Reasoning 27B?
Q4_K_M · 17.4 GB21 devices with unified memory can run Pantheon Reasoning 27B, including NVIDIA DGX H100, NVIDIA DGX A100 640GB, Mac Mini M4 Pro (24 GB).
Runs great
— Plenty of headroomRelated Models
Derivatives (1)
Frequently Asked Questions
- How much VRAM does Pantheon Reasoning 27B need?
Pantheon Reasoning 27B requires 17.4 GB of VRAM at Q4_K_M, or 28.5 GB at Q8_0. Full 262K context adds up to 56.8 GB (74.2 GB total).
VRAM = Weights + KV Cache + Overhead
Weights = 27.8B × 4.8 bits ÷ 8 = 16.7 GB
KV Cache + Overhead ≈ 0.7 GB (at 2K context + ~0.3 GB framework)
KV Cache + Overhead ≈ 57.5 GB (at full 262K context)
VRAM usage by quantization
Q4_K_M17.4 GBQ4_K_M + full context74.2 GB- Can NVIDIA GeForce RTX 4090 run Pantheon Reasoning 27B?
Yes, at Q6_K (23.7 GB) or lower. Higher quantizations like Q8_0 (28.5 GB) exceed the NVIDIA GeForce RTX 4090's 24 GB.
- What's the best quantization for Pantheon Reasoning 27B?
For Pantheon Reasoning 27B, Q4_K_M (17.4 GB) offers the best balance of quality and VRAM usage. Q4_K_L (17.8 GB) provides better quality if you have the VRAM. The smallest option is IQ2_XXS at 8.4 GB.
VRAM requirement by quantization
IQ2_XXS8.4 GBQ2_K12.6 GBQ3_K_L15.0 GBQ4_K_M ★17.4 GBQ4_K_L17.8 GBQ8_028.5 GB★ Recommended — best balance of quality and VRAM usage.
- Can I run Pantheon Reasoning 27B on a Mac?
Pantheon Reasoning 27B requires at least 8.4 GB at IQ2_XXS, 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 Pantheon Reasoning 27B locally?
Yes — Pantheon Reasoning 27B can run locally on consumer hardware. At Q4_K_M quantization it needs 17.4 GB of VRAM. Popular tools include Ollama, LM Studio, and llama.cpp.
- How fast is Pantheon Reasoning 27B?
At Q4_K_M, Pantheon Reasoning 27B can reach ~167 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 ÷ 17.4 × 0.55 = ~167 tok/s
Estimated speed at Q4_K_M (17.4 GB)
~167 tok/s~38 tok/s~125 tok/s~104 tok/sReal-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.
- What's the download size of Pantheon Reasoning 27B?
At Q4_K_M, the download is about 16.67 GB. The full-precision Q8_0 version is 27.78 GB. The smallest option (IQ2_XXS) is 7.64 GB.
- Which GPUs can run Pantheon Reasoning 27B?
6 consumer GPUs can run Pantheon Reasoning 27B at Q4_K_M (17.4 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 Pantheon Reasoning 27B?
21 devices with unified memory can run Pantheon Reasoning 27B at Q4_K_M (17.4 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.