What GPU do I need to run ornith-ai/Ornith-1.5-35B-A3B?
36.0B parameters, published in BF16. View on Hugging Face
Set up Ornith-1.5-35B-A3BOrnith-1.5-35B-A3B is published by ornith-ai on Hugging Face, with 206,651 downloads and 521 likes to date. It's a Qwen3_5MoeForConditionalGeneration model built for text-generation, published natively in BF16.
VRAM required & cheapest live GPU fit
Required VRAM = weight size at each precision times a flat 1.2 overhead for activations and fragmentation. The KV-cache grows with context and is not in that factor; it is listed per model below where the architecture is published. Full formula and assumptions: methodology.
| Precision | Weight size | Required VRAM | Cheapest live fit | GPUs needed | Est. $/hr (full fit) |
|---|---|---|---|---|---|
| BF16 | 67.0 GB | 80.4 GB | RTX PRO 6000 WS | 1 | $1.62/hr |
| cheaper alt. | RTX A5000 | 4 | $0.704/hr | ||
| FP8 (quantized) | 33.5 GB | 40.2 GB | L40 | 1 | $0.759/hr |
| cheaper alt. | RTX 4000 SFF Ada | 3 | $0.594/hr | ||
| INT4 (quantized) | 16.7 GB | 20.1 GB | RTX A5000 | 1 | $0.176/hr |
A GPU is only matched to a row if its hardware supports that precision, and the primary recommendation is always a single-GPU fit when one exists.
INT4 requires a quantized checkpoint actually published for this model, check its Hugging Face page before relying on this row.
Cheapest way to run Ornith-1.5-35B-A3B at its published (BF16) precision: 1× RTX PRO 6000 WS, at $1.62/hr per GPU ($1.62/hr total). Quantizing to FP8 or INT4 (rows above) can cost less, but requires a compatible quantized checkpoint to exist for this model.
Ornith-1.5-35B-A3B: KV cache by context length
The KV cache is the memory the attention layers hold for every token of context, on top of the weights. It is not part of the flat 1.2x overhead in the table above, grows with context length and with every concurrent request, and is why a long-context deployment needs more VRAM than the table shows.
Hybrid: only the full-attention layers cache per token; the other layers keep a fixed-size state. Cached per token: 20,480 bytes at 16-bit.
| Context | KV cache, one sequence |
|---|---|
| 4K | 0.08 GB |
| 32K | 0.63 GB |
| 128K | 2.5 GB |
| 256K (model maximum) | 5.0 GB |
Computed from the layer, head and window counts in the model's own configuration (ornith-ai/Ornith-1.5-35B-A3B), at 16 bits per cached value. Each concurrent sequence needs its own cache, on top of the weights.
Ornith-1.5-35B-A3B: common questions
Can Ornith-1.5-35B-A3B run on a single GPU?
Yes, but not on a desktop card. At BF16 it needs 80.4 GB of VRAM, more than a single 32 GB desktop card holds. The cheapest live single-card fit is a 96.0 GB RTX PRO 6000 WS at $1.62/hr.
What is the least VRAM Ornith-1.5-35B-A3B can run in?
20.1 GB, at INT4 (quantized), which fits a 24 GB card, against 80.4 GB at BF16. That row assumes an INT4 checkpoint has actually been published for this model, so check its Hugging Face page before planning around it.
Does quantizing Ornith-1.5-35B-A3B lower the GPU bill?
Yes. At BF16 the cheapest live fit is one RTX PRO 6000 WS at $1.62/hr. At INT4 (quantized) it drops to one RTX A5000 at $0.176/hr, provided a quantized checkpoint exists for it.
Weight-to-VRAM math, the fit rules, and how live prices are normalized: full methodology.
More Ornith 1 models
- Ornith-1.5-35B-A3B-FP8 (36.0B, F8_E4M3)
- Ornith-1.0-35B-FP8 (35.1B, F8_E4M3)
- Ornith-1.0-35B-AWQ-FP8 (35.1B, F8_E4M3)
- Ornith-1.0-35B-FP8 (35.1B, F8_E4M3)
- Ornith-1.0-35B-FP8 (35.1B, F8_E4M3)
Alternatives at this size
Other models for text-generation within about a third of Ornith-1.5-35B-A3B's 36.0B parameters, from other model lines.
- Qwen3-32B (32.8B, BF16)
- GLM-4.7-Flash (31.2B, BF16)
- NVIDIA-Nemotron-3-Nano-30B-A3B-BF16 (31.6B, BF16)
- granite-4.1-30b (28.9B, BF16)
- Kimi-Linear-48B-A3B-Instruct (49.1B, BF16)
More on Ornith-1.5-35B-A3B
Fits on a 96 GB GPU at BF16: every model that fits in 96 GB.
Fits on a 48 GB GPU at FP8: every model that fits in 48 GB.
Fits on a 24 GB GPU at INT4: every model that fits in 24 GB.
Best chat and assistants models: how Ornith-1.5-35B-A3B ranks against the rest.
Related reading: RTX PRO 6000 WS pricing and specs, How much VRAM you need for LLMs, Serving LLMs with vLLM, vLLM vs TensorRT-LLM vs SGLang, and Best GPU for LLM inference.
