LFM2.5 1.2B Thinking — Hardware Requirements & GPU Compatibility
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LFM2.5 1.2B Thinking is a 1.2B-parameter open language model from LiquidAI. It supports a context window of up to 128,000 tokens. At Q4_K_M it needs about 1.07 GB of VRAM — see which GPUs and Macs can run it below.
30.9K downloads
361 likesSpecifications
- Publisher
- LiquidAI
- Parameters
- 1.2B
- Architecture
- Lfm2ForCausalLM
- Context Length
- 128,000 tokens
- Vocabulary Size
- 65,536
- Release Date
- 2026-01-20
- License
- Other
Get Started
HuggingFace
How Much VRAM Does LFM2.5 1.2B Thinking Need?
Select a quantization to see compatible GPUs below.
| Quantization | Bits | VRAM | + Context | File Size | Quality |
|---|---|---|---|---|---|
| Q2_Kest. | 3.40 | 0.9 GB | 5.0 GB | 0.50 GB | 2-bit quantization with K-quant improvements |
| Q3_K_Mest. | 3.90 | 0.9 GB | 5.1 GB | 0.57 GB | 3-bit medium quantization |
| Q4_0 | 4.00 | 0.9 GB | 5.1 GB | 0.59 GB | 4-bit legacy quantization |
| Q4_K_M | 4.80 | 1.1 GB | 5.2 GB | 0.70 GB | 4-bit medium quantization — most popular sweet spot |
| Q5_K_M | 5.70 | 1.2 GB | 5.3 GB | 0.83 GB | 5-bit medium quantization — good quality/size tradeoff |
| Q6_K | 6.60 | 1.3 GB | 5.5 GB | 0.97 GB | 6-bit quantization, very good quality |
| Q8_0 | 8.00 | 1.5 GB | 5.7 GB | 1.17 GB | 8-bit quantization, near-lossless |
| BF16 | 16.00 | 2.7 GB | 6.8 GB | 2.34 GB | Brain floating point 16 — preferred for training |
est.= calculated VRAM estimate; no published GGUF file found for that quantization yet. Other rows are verified against real community uploads.
Which GPUs Can Run LFM2.5 1.2B Thinking?
Q4_K_M · 1.1 GBLFM2.5 1.2B Thinking (Q4_K_M) requires 1.1 GB of VRAM to load the model weights. For comfortable inference with headroom for KV cache and system overhead, 2+ GB is recommended. Using the full 128K context window can add up to 4.1 GB, bringing total usage to 5.2 GB. 50 GPUs can run it, including NVIDIA GeForce RTX 5090, NVIDIA GeForce RTX 3090 Ti.
Runs great
— Plenty of headroomWhich Devices Can Run LFM2.5 1.2B Thinking?
Q4_K_M · 1.1 GB59 devices with unified memory can run LFM2.5 1.2B Thinking, including NVIDIA DGX H100, NVIDIA DGX A100 640GB.
Runs great
— Plenty of headroomWhere to Download LFM2.5 1.2B Thinking
Community quantizations of this model — GGUF for llama.cpp, Ollama, and LM Studio, plus AWQ/MLX variants where available.
Related Models
Frequently Asked Questions
- How much VRAM does LFM2.5 1.2B Thinking need?
LFM2.5 1.2B Thinking requires 1.1 GB of VRAM at Q4_K_M, or 2.7 GB at BF16. Full 128K context adds up to 4.1 GB (5.2 GB total).
VRAM = Weights + KV Cache + Overhead
Weights = 1.2B × 4.8 bits ÷ 8 = 0.7 GB
KV Cache + Overhead ≈ 0.4 GB (at 2K context + ~0.3 GB framework)
KV Cache + Overhead ≈ 4.5 GB (at full 128K context)
VRAM usage by quantization
Q4_K_M1.1 GBQ4_K_M + full context5.2 GB- What's the best quantization for LFM2.5 1.2B Thinking?
For LFM2.5 1.2B Thinking, Q4_K_M (1.1 GB) offers the best balance of quality and VRAM usage. Q5_K_M (1.2 GB) provides better quality if you have the VRAM. The smallest option is Q2_K at 0.9 GB.
VRAM requirement by quantization
Q2_K0.9 GBQ4_00.9 GBQ4_K_M ★1.1 GBQ5_K_M1.2 GBQ6_K1.3 GBBF162.7 GB★ Recommended — best balance of quality and VRAM usage.
- Can I run LFM2.5 1.2B Thinking on a Mac?
LFM2.5 1.2B Thinking requires at least 0.9 GB at Q2_K, 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 LFM2.5 1.2B Thinking locally?
Yes — LFM2.5 1.2B Thinking can run locally on consumer hardware. At Q4_K_M quantization it needs 1.1 GB of VRAM. Popular tools include Ollama, LM Studio, and llama.cpp.
- How fast is LFM2.5 1.2B Thinking?
At Q4_K_M, LFM2.5 1.2B Thinking can reach ~4112 tok/s on AMD Instinct MI350X. On NVIDIA GeForce RTX 4090: ~612 tok/s. Speed depends mainly on GPU memory bandwidth. Real-world results typically within ±20%.
tok/s = (bandwidth GB/s ÷ model GB) × efficiency
Example: NVIDIA B200 → 8000 ÷ 1.1 × 0.65 = ~4860 tok/s
Estimated speed at Q4_K_M (1.1 GB)
~4860 tok/s~612 tok/s~4860 tok/s~4112 tok/sReal-world results typically within ±20%. Speed depends on batch size, quantization kernel, and software stack.
- What's the download size of LFM2.5 1.2B Thinking?
At Q4_K_M, the download is about 0.70 GB. The full-precision BF16 version is 2.34 GB. The smallest option (Q2_K) is 0.50 GB.
- Which GPUs can run LFM2.5 1.2B Thinking?
50 consumer GPUs can run LFM2.5 1.2B Thinking at Q4_K_M (1.1 GB). Top options include AMD Radeon RX 6700 XT, AMD Radeon RX 6800, AMD Radeon RX 6800 XT. 50 GPUs have plenty of headroom for comfortable inference.
- Which devices can run LFM2.5 1.2B Thinking?
59 devices with unified memory can run LFM2.5 1.2B Thinking at Q4_K_M (1.1 GB), including AMD Ryzen AI 9 HX 370 (Strix Point) Laptop, ASUS Ascent GX10, Apple iPhone 17 Pro, Asus ROG Flow Z13 (2025, Ryzen AI Max+ 395, 128 GB). Apple Silicon Macs use unified memory shared between CPU and GPU, making them well-suited for local LLM inference.