Can you run Nex N2.5 Pro locally?
Nex family · Sep 2026 · 396.8B parameters · Hugging Face model card
Nex N2.5 Pro is a mixture-of-experts model activating 10 of 512 experts per token released with open weights on Hugging Face: 396.8B total parameters, a 262,144-token context window, apache-2.0 license. Running it locally needs roughly 256 GB of memory at Q4-class quantization (calculated) — multi-GPU server or large-unified-memory territory. Measured local speeds: not yet published here; we list unknowns as unknowns.
Minimum: 256 GB+ memory (Q4-class, calculated) · Recommended: 384 GB+ for comfortable context headroom (Q4-class, calculated)
How much VRAM does Nex N2.5 Pro need at each quantization?
Nex N2.5 Pro needs 261.9 GB of VRAM at Q4_K_M. The table below lists weights-only size and total VRAM including overhead for each common quantization level with 4k and 32k token contexts.
| Quantization | Bits / weight | Weights only | Total + KV @4k ctx | Total + KV @32k ctx |
|---|---|---|---|---|
| Q4_K_M | 4.8 | 238.1 GB | 261.9 GB | 261.9 GB |
| Q5_K_M | 5.7 | 282.7 GB | 311.0 GB | 311.0 GB |
| Q6_K | 6.6 | 327.4 GB | 360.1 GB | 360.1 GB |
| Q8_0 | 8.5 | 421.6 GB | 463.8 GB | 463.8 GB |
| FP16 | 16 | 793.6 GB | 873.0 GB | 873.0 GB |
Method: weights = parameters × bits-per-weight (Q4_K_M ≈ 4.8, Q5_K_M ≈ 5.7, Q6_K ≈ 6.6, Q8_0 ≈ 8.5, FP16 = 16), plus 10% loading overhead, plus KV cache from the verified architecture config (not applicable to this architecture). Source: HF-verified 2026-09-15 via api (repo safetensors + config.json); VRAM figures are documented calculations, not measurements
Which GPUs can run Nex N2.5 Pro locally?
At Q4_K_M with a 4k context, Nex N2.5 Pro needs 261.9 GB of VRAM. The lists below are computed live from our GPU database and grouped by how much headroom the card has. Disclosure: CompareAIHardware.com participates in the Amazon Associates program and earns from qualifying purchases through links on this page. Affiliate relationships do not influence our recommendations.
Minimum GPUs that fit Nex N2.5 Pro at Q4_K_M
These GPUs hold the model but leave little headroom — keep contexts short.
| GPU | VRAM | Bandwidth | Type | |
|---|---|---|---|---|
| AMD Instinct MI355X | 288 GB | 8000 GB/s | Data Center GPU | |
| NVIDIA B300 (Blackwell Ultra) | 288 GB | 8000 GB/s | Data Center GPU |
Needs 2+ GPUs to run Nex N2.5 Pro
One of these cards is too small on its own, but a pair (tensor or pipeline parallel, ~90% efficiency) covers the 261.9 GB requirement. See our multi-GPU guide for setup.
| GPU | VRAM | Bandwidth | Type | |
|---|---|---|---|---|
| AMD Instinct MI300X | 192 GB ×2 | 5300 GB/s | Data Center GPU | |
| NVIDIA B200 | 192 GB ×2 | 8000 GB/s | Data Center GPU | |
| AMD Instinct MI325X | 256 GB ×2 | 6000 GB/s | Data Center GPU |