Liquid LFM3 1.7B on RTX 5090 D (32GB) — VRAM, KV Cache & Throughput

Liquid LFM3 1.7B (1.7B total, 1.7B active, Hybrid Linear + Full Attention) uses 1.06 GiB of 4-bit weights (Q4_K_M), requiring 1.73 GiB total at 8K context and 2.01 GiB at 32K on RTX 5090 D (~380 tok/s decode).

Interactive Sizing Workbench

Full Compatibility Report →
32 GB · 1792 GB/s
Fits with Safe Headroom
Config-derived formula HF config.json ↗
Memory Allocation Breakdown (GiB) 1.73 GiB (1.86 GB) / 32 GiB (5%)
Model Weights: 1.06 GiB KV Cache & State: 0.11 GiB Runtime & Activation Buffers: 0.56 GiB System RAM Offload: 0 GiB
Required GPU Memory
1.73 GiB
1.86 GB (decimal)
Usable Hardware Memory
30.4 GiB
32 GB (physical)
Safe Headroom
+28.67 GiB
5% utilization
Est. Decode Throughput
~380 tok/s
1.7B active params
Est. Prefill Throughput
~24000 tok/s
4K Prompt TTFT: ~171 ms
Est. Cost / 1M Tokens
$0.04
Hybrid Linear + Full Attention · Apache-2.0

Recommended Hardware for Current Configuration

Best Single GPU
RTX 4060 Ti 16GB (16GB)
~$430
Best Value / Used GPU
RTX 3060 12GB (12GB)
~$280
Apple Unified Memory
Ryzen AI Max+ 395 128GB
~$1,999
Cloud From
Vast.ai · $0.06 / hr
1x RTX 3060 12GB

Production Launch Commands

llama.cpp (GGUF)
llama-server -hf LiquidAI/LFM3-1.7B-GGUF:Q4_K_M \
  --ctx-size 8192 -ngl 999 --flash-attn
vLLM
vllm serve LiquidAI/LFM3-1.7B \
  --max-model-len 8192 --gpu-memory-utilization 0.92
Live Token Speed Simulator (TTFT ~171ms · ~380 tok/s)
[Liquid LFM3 1.7B · 1.73 GiB] allocated on target GPU. Prefill completed in TTFT window; streaming autoregressive tokens at memory-bandwidth-bound rate...

Cloud GPU Comparison & Rent-vs-Buy TCO

Verified public rates across RunPod, Vast.ai, Vultr, and DigitalOcean.

Verified: 2026-11-04
Purchase break-even
~18.5 months
Est. local power: $3.51 / mo
Provider Recommended Instance Total VRAM Hourly Rate Monthly at Selected Hours Billing Mode Deploy
RunPod 1x RTX 3090 (Community Cloud) 24 GB $0.22 / hr $26.75 / mo Per-second Deploy GPU ↗
Vast.ai 1x RTX 3060 12GB (Verified Host) 12 GB $0.06 / hr $7.42 / mo Spot / On-demand Deploy GPU ↗
Vultr ($300 Free Credit*) 1x L40S 48GB (Dedicated Instance · $300 Credit*) 48 GB $1.67 / hr $203.19 / mo Hourly Deploy GPU ↗
Vultr Cloud GPU 1x L40S 48GB (Dedicated Instance) 48 GB $1.67 / hr $203.19 / mo Hourly Deploy GPU ↗
DigitalOcean 1x RTX 6000 Ada (Dedicated Instance) 48 GB $1.57 / hr $190.91 / mo Per-second Deploy GPU ↗

Rates reflect public listings on the verification date and fluctuate with regional inventory.

Fine-Tuning VRAM Requirements (QLoRA / LoRA / Full) — Liquid LFM3 1.7B

QLoRA (4b) Fits with Safe Headroom
3.27 GiB
Model Weights: 1.06 GiB · Gradients + Optimizer: 1.2 GiB · Act: 1.01 GiB
Recommended GPU: RTX 4060 Ti 16GB (16GB)
LoRA (16b) Fits with Safe Headroom
6.31 GiB
Model Weights: 3.17 GiB · Gradients + Optimizer: 1.8 GiB · Act: 1.34 GiB
Recommended GPU: RTX 4060 Ti 16GB (16GB)
Full BF16 Fits with Safe Headroom
15.36 GiB
Model Weights: 3.17 GiB · Gradients + Optimizer: 9.83 GiB · Act: 2.36 GiB
Recommended GPU: Arc Pro B60 24GB (24GB)

Engineering Sizing Notes & Optimization Playbook

Quick Hardware Verdict

RTX 5090 D (32GB physical, 30.4 GiB usable) runs 4-bit (Q4_K_M) Liquid LFM3 1.7B at 8K context using 1.73 GiB with 28.67 GiB of safe headroom (~380 tok/s single-stream decode).

KV Cache & Runtime Tuning

Liquid LFM3 1.7B uses Hybrid Linear + Full Attention (1.7B total, 1.7B active per token). Moving from 8K to 32K context expands FP16 KV cache from 0.11 GiB to 0.39 GiB; enabling 8-bit KV cache (llama.cpp -ctk q8_0 -ctv q8_0 or vLLM --kv-cache-dtype fp8) saves 0.19 GiB at 32K (reducing total VRAM to 1.82 GiB).

VRAM Scaling Across Context Windows (4K to 128K, 4-bit Weights)

Liquid LFM3 1.7B VRAM scaling from 4K to 128K context (4K: 1.67 GiB, 8K: 1.73 GiB, 32K: 2.01 GiB, 128K: 3.13 GiB) 4K 1.67 GiB (KV 0.06 GiB) 8K 1.73 GiB (KV 0.11 GiB) 32K 2.01 GiB (KV 0.39 GiB) 128K 3.13 GiB (KV 1.51 GiB) RTX 5090 D (32GB)
Model weights remain constant while attention KV cache grows with context length and batch size.

Quantization Precision & Memory Matrix — Liquid LFM3 1.7B @ 8K

Quantization Format Weights (GiB) KV Cache Total VRAM (GiB) Decode Speed Compatibility (RTX 5090 D) Recommended GPU Data Source
Native Weights (BF16 / FP8 / MXFP4 — Lossless) (BF16) 3.17 GiB 0.11 GiB 3.84 GiB (4.12 GB) ~271.9 tok/s Fits with Safe Headroom RTX 4060 Ti 16GB (16GB) Official checkpoint size
FP8 / GGUF Q8_0 (8-bit — Near-Lossless) (Q8_0) 1.68 GiB 0.11 GiB 2.35 GiB (2.52 GB) ~380 tok/s Fits with Safe Headroom RTX 4060 Ti 16GB (16GB) Config-derived formula
GGUF Q6_K (6-bit — High Precision) (Q6_K) 1.3 GiB 0.11 GiB 1.97 GiB (2.12 GB) ~380 tok/s Fits with Safe Headroom RTX 4060 Ti 16GB (16GB) Config-derived formula
GGUF Q5_K_M (5-bit — Balanced) (Q5_K_M) 1.18 GiB 0.11 GiB 1.85 GiB (1.99 GB) ~380 tok/s Fits with Safe Headroom RTX 4060 Ti 16GB (16GB) Config-derived formula
Q4_K_M / UD-Q4_K_XL / AWQ (4-bit — Recommended) (Q4_K_M) 1.06 GiB 0.11 GiB 1.73 GiB (1.86 GB) ~380 tok/s Fits with Safe Headroom RTX 4060 Ti 16GB (16GB) Config-derived formula
GGUF IQ4_XS (4.25-bit — Compact) (IQ4_XS) 0.92 GiB 0.11 GiB 1.59 GiB (1.71 GB) ~380 tok/s Fits with Safe Headroom RTX 4060 Ti 16GB (16GB) Config-derived formula
GGUF Q3_K_M (3-bit — Low VRAM) (Q3_K_M) 0.84 GiB 0.11 GiB 1.51 GiB (1.62 GB) ~380 tok/s Fits with Safe Headroom RTX 4060 Ti 16GB (16GB) Config-derived formula
GGUF UD-Q2_K_XL (2-bit — Extreme MoE) (UD-Q2_K_XL) 0.65 GiB 0.11 GiB 1.32 GiB (1.42 GB) ~380 tok/s Fits with Safe Headroom RTX 4060 Ti 16GB (16GB) Config-derived formula

Technical Specifications & FAQ

Does Liquid LFM3 1.7B fit on RTX 5090 D (32GB)?

In 4-bit (Q4_K_M) at 8,192 context, Liquid LFM3 1.7B requires 1.73 GiB total GPU memory (1.06 GiB weights + 0.11 GiB KV cache + 0.56 GiB runtime buffers) against 30.4 GiB usable on RTX 5090 D, delivering ~380 tok/s decode.

How much VRAM does Liquid LFM3 1.7B need at 32K context?

At 32,768 context tokens, Liquid LFM3 1.7B (Hybrid Linear + Full Attention) allocates 0.39 GiB for KV cache and state, bringing total 4-bit VRAM to 2.01 GiB (2.16 GB decimal).

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