Can I Run Nex-N2.5 on RTX 4090 Laptop (16 GB VRAM, 32 GB RAM)?

Written by Jakub Rusinowski · Last updated September 8, 2026

Yes

Yes — Nex-N2.5 mini at Q2_K needs about 14.2 GB of the 16 GB usable on RTX 4090 Laptop (16 GB VRAM, 32 GB RAM) (~1.8 GB spare), at ~171.6 tok/s (estimated), with room for about 8,192 tokens of context.

Confidence: medium · Recommended quantization: Q2_K · Estimated speed: ~171.6 tok/s

Buy This HardwareAMD Radeon RX 9060 XT 16GB — 16 GB VRAM · 160 W board power Deploy in the Cloud NowRTX 4090 on RunPod — from $0.34/hr · rate checked 2026-07

or compare on Vast.ai from $0.35/hr (typical low · varies)

As an Amazon Associate we earn from qualifying purchases. Cloud GPU links are referral links — we may earn a commission at no extra cost to you.

RTX 4090 Laptop (16 GB VRAM, 32 GB RAM) — what it gives a model

Usable memory for models	16 GB
Memory bandwidth	717 GB/s
Form factor	Laptop
Operating system	Windows or Linux
Memory upgradeable	Yes

Nex-N2.5 on RTX 4090 Laptop (16 GB VRAM, 32 GB RAM): memory by quantization

Quant	Memory needed	Fits 16 GB?	Max context	Est. speed	Download
F16	72.7 GB	✗ No	—	—	70 GB
Q8_0	39.9 GB	✗ No	—	—	37.2 GB
Q6_K	31.4 GB	✗ No	—	—	28.7 GB
Q5_K_M	27.5 GB	✗ No	—	—	24.8 GB
Q4_K_M	23.8 GB	✗ No	—	—	21.1 GB
Q3_K_M	17.6 GB	✗ No	—	—	14.9 GB
Q2_K	14.2 GB	✓ Yes	8K	~171.6 tok/s	11.5 GB

Which Nex-N2.5 sizes fit

Variant	Needs at Q4_K_M	Fits?	Est. speed
Nex-N2.5 Max	967.4 GB	✗ Too large	—
Nex-N2.5 Pro	244.7 GB	✗ Too large	—
Nex-N2.5 mini	23.8 GB	✗ Too large	—

What to watch out for

Q2_K is the only quantization that fits, and it is a heavily degraded one — expect noticeably worse output than the same model at Q4_K_M. A smaller model at Q4 is usually the better trade.
3 larger variants of Nex-N2.5 do not fit and would need CPU offload or different hardware.
This model does not publish its full attention configuration, so the KV-cache share of these figures is inferred from its parameter count rather than computed exactly.

RTX 4090 laptop limitations

A mobile RTX 4090 carries 16 GB, not the desktop card's 24 GB, and is closer to a desktop 4080 in throughput — which is why it is modelled against that chip here.
Sustained throughput depends on the chassis power limit; thin laptops throttle well below the quoted figures.

Recommended setup

Ollama or llama.cpp (CUDA/ROCm) — vLLM if you need concurrent serving

How these numbers are calculated

Memory need = quantized weights + KV cache at 8,192 tokens (f16) + 0.8 GB runtime overhead.
16 GB of VRAM on the NVIDIA GeForce RTX 4080 at 717 GB/s.
32 GB of system RAM available for CPU offload when a model exceeds VRAM.
Throughput is a memory-bandwidth roofline estimate, not a measurement. It is labelled "estimated" everywhere it appears.
KV cache is inferred from the parameter count because this model does not publish its full attention configuration.

FAQ