HARDWARE FIT CHECK • Qwen 3.8 27B Instruct + NVIDIA GeForce RTX 4090 (24GB GDDR6X)21.93 GB / 24 GB VRAM

Can I Run Qwen 3.8 27B Instruct on NVIDIA GeForce RTX 4090 (24GB GDDR6X)?

Full VRAM footprint analysis, tokens/sec generation benchmark, and copy-paste Ollama & vLLM runtime commands for running Qwen 3.8 27B Instruct (27.2B) on NVIDIA GeForce RTX 4090 (24GB GDDR6X) (24 GB).

⚡ Fits in VRAM (Tight Headroom — Use Q8/Q4 KV Cache)21.93 GB (91%)~40 t/s

Model & Target Hardware

interactive
Agentic Coding, Terminal Workflows & Multi-File Refactoring
Qwen 3.8 27B Instruct on NVIDIA GeForce RTX 4090 (24GB GDDR6X)

⚡ Tight Fit — Runs 100% on GPU (Low Headroom)

⚡ TIGHT FIT
Required VRAM
21.93 GB
91% of hardware capacity (24 GB)
Est. Decode Speed
~40 tok/s
Dense model @ 1008 GB/s
Available Headroom
+2.07 GB
Safe for OS display & full context
Memory Allocation & Headroom
21.93 GB allocated of 24 GB capacity
91% utilized
Weights: 16.32 GB
KV: (32K): 4.29 GB
Overhead: 1.32 GB
Free Headroom: +2.07 GB
⚡ Architecture & Throughput Transparency: Single-user decode speed (~40 tok/s) is memory-bandwidth bound at batch size = 1 on NVIDIA GeForce RTX 4090 (24GB GDDR6X) (1008 GB/s). Prompt prefill / TTFT (~580 tok/s) is compute-bound and utilizes GPU Tensor cores. Actual latency varies with FlashAttention-2 and runtime engine (Ollama/vLLM/llama.cpp).
OLLAMA_FLASH_ATTENTION=1 OLLAMA_KV_CACHE_TYPE=q8_0 ollama run qwen3.8:27b

Quantization Precision Matrix

32K ctx • KV: Q8_0
QuantizationWeightsKV CacheTotal VRAMEst. SpeedFit Status
FP1616 bpw54.4 GB4.29 GB61.34 GB (256%)0 t/sOOM
Q8_08.5 bpw28.83 GB4.29 GB34.88 GB (145%)0 t/sOOM
Q6_K6.56 bpw22.3 GB4.29 GB28.12 GB (117%)~6 t/sPARTIAL
Q5_K_M5.68 bpw19.31 GB4.29 GB25.03 GB (104%)~7 t/sPARTIAL
Q4_K_M4.8 bpw16.32 GB4.29 GB21.93 GB (91%)~40 t/sFITS
FP44.25 bpw14.42 GB4.29 GB19.96 GB (83%)~44 t/sFITS
IQ3_XS3.3 bpw11.15 GB4.29 GB16.58 GB (69%)~56 t/sFITS

Local Hardware Configurations & Pricing

High-bandwidth VRAM specs and current market prices
Consumer GPU24 GB VRAM

NVIDIA GeForce RTX 4090 (24GB GDDR6X)

The 24GB CUDA enthusiast standard for 14B–32B Q4_K_M models

1008 GB/s450W TDP
Consumer GPU32 GB VRAM

NVIDIA GeForce RTX 5090 (32GB GDDR7)

Maximum tokens/sec on 27B–35B models & Blackwell FP4 quantization

1792 GB/s575W TDP
Multi-GPU Rig48 GB VRAM

2x NVIDIA RTX 3090 Dual Rig (48GB Total VRAM)

Best price-to-VRAM homelab rig for 70B Q4_K_M & Qwen 3.8 27B Q8

936 GB/s700W TDP
Consumer GPU16 GB VRAM

NVIDIA GeForce RTX 5080 (16GB GDDR7)

Blazing fast 8B–14B coding models with FP4/Q6_K precision

960 GB/s360W TDP

Export Full Architecture & Infrastructure Spec

Get an executive-ready PDF report with exact memory math, hardware benchmarks, and cost comparisons.