HARDWARE FIT CHECK • Qwen 3.8 27B Instruct + NVIDIA GeForce RTX 3090 (24GB GDDR6X)21.93 GB / 24 GB VRAM

Can I Run Qwen 3.8 27B Instruct on NVIDIA GeForce RTX 3090 (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 3090 (24GB GDDR6X) (24 GB).

• TIGHT FIT21.93 GB (91%)~35 t/s

Target Hardware & Model

interactive
Agentic coding, terminal workflows & multi-file refactoring on 24GB–48GB GPUs and Apple Silicon
Qwen 3.8 27B Instruct on NVIDIA GeForce RTX 3090 (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
~35 tok/s
Dense model @ 936 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 (~35 tok/s) is memory-bandwidth bound at batch size = 1 on NVIDIA GeForce RTX 3090 (24GB GDDR6X) (936 GB/s). Prompt prefill / TTFT (~508 tok/s) is compute-bound and utilizes GPU Tensor cores. Actual latency varies with FlashAttention-2 and runtime engine (Ollama/vLLM/llama.cpp).

Local Hardware Configurations & Pricing

Tight Fit: Consider 32GB+ for Safe Headroom
High-bandwidth VRAM specs and current market prices
Consumer GPU↑ Upgrade
32 GB VRAM

NVIDIA GeForce RTX 5090 (32GB GDDR7)

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

1792 GB/s575W TDP
Consumer GPU
24 GB VRAM

NVIDIA GeForce RTX 4090 (24GB GDDR6X)

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

1008 GB/s450W TDP
Multi-GPU Rig↑ Upgrade
48 GB VRAM

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

Best price-to-VRAM homelab rig for Llama 3.3 70B Q4_K_M & Qwen 2.5 Coder 32B Q8_0

1648 GB/s700W TDP
Consumer GPU
24 GB VRAM

NVIDIA GeForce RTX 3090 (24GB GDDR6X)

The #1 budget 24GB card for local LLMs, running 14B–32B models and Q4 70B quantized

936 GB/s350W TDP

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%)~35 t/sFITS
FP44.25 bpw14.42 GB4.29 GB19.96 GB (83%)~39 t/sFITS
IQ3_XS3.3 bpw11.15 GB4.29 GB16.58 GB (69%)~50 t/sFITS
FAQ & Reference

Frequently Asked Questions: Qwen 3.8 27B Instruct on NVIDIA GeForce RTX 3090 (24GB GDDR6X)

How much VRAM does Qwen 3.8 27B Instruct need on NVIDIA GeForce RTX 3090 (24GB GDDR6X)?

At standard 4-bit quantization (Q4_K_M) with 32K context, Qwen 3.8 27B Instruct requires 21.93 GB of total VRAM (weights + KV cache + CUDA runtime overhead).

What inference speed will Qwen 3.8 27B Instruct achieve on NVIDIA GeForce RTX 3090 (24GB GDDR6X)?

Based on NVIDIA GeForce RTX 3090 (24GB GDDR6X)'s 936 GB/s memory bandwidth, expected decode speed is approximately 35 tokens per second.

Can I expand context beyond 32K tokens?

Each additional 32K tokens of context requires additional KV cache memory. For longer context windows, consider 8-bit or 4-bit KV cache quantization.