What is the biggest model the RTX 4090 can run?

Qwen3 32B, which needs about 22 GB, on the 24 GB version at about 28 tok/s.

What is the biggest model the RTX 5090 can run?

Qwen3 32B, which needs about 22 GB, on the 32 GB version at about 49 tok/s.

RTX 4090 vs RTX 5090 for local AI

Q: Which is better for local AI, the RTX 4090 or the RTX 5090?

The RTX 5090, for speed. They fit the same models. Both fit the same models we track, up to Qwen3 32B. The RTX 5090 generates about 78% faster on any model both can run, because it has 1792 GB/s of memory bandwidth to the RTX 4090's 1008 GB/s.

Both fit the same models we track, up to Qwen3 32B. The RTX 5090 generates about 78% faster on any model both can run, because it has 1792 GB/s of memory bandwidth to the RTX 4090's 1008 GB/s.

The numbers that matter

Memory and bandwidth

Memory decides which models fit. Bandwidth decides how fast they generate, because every token reads the model's active weights once.

	RTX 4090	RTX 5090
Memory	24 GB VRAM	32 GB VRAM
Bandwidth	1008 GB/s	1792 GB/s
Biggest model that fits	Qwen3 32B	Qwen3 32B
Best everyday pick	Qwen3 32B, ~28 tok/s	Qwen3 32B, ~49 tok/s

Model by model

Every model, side by side

Estimated generation speed at the largest memory size each was sold in (24 GB and 32 GB).

Model	RTX 4090	RTX 5090
Qwen3 4B About 4 GB	~220 tok/s Runs great	~390 tok/s Runs great
Qwen3 8B About 7 GB	~110 tok/s Runs great	~190 tok/s Runs great
Gemma 3 12B About 10 GB	~68 tok/s Runs great	~120 tok/s Runs great
Qwen3 14B About 11 GB	~60 tok/s Runs great	~110 tok/s Runs great
gpt-oss 20B About 16 GB	~180 tok/s Runs great	~310 tok/s Runs great
Gemma 3 27B About 19 GB	~33 tok/s Runs great	~58 tok/s Runs great
Qwen3 30B-A3B About 21 GB	~180 tok/s Runs great	~310 tok/s Runs great
Qwen3 32B About 22 GB	~28 tok/s Usable	~49 tok/s Runs great
Llama 3.3 70B About 45 GB	Needs 45 GB	Needs 45 GB
gpt-oss 120B About 67 GB	Needs 67 GB	Needs 67 GB
Qwen3 235B-A22B About 144 GB	Needs 144 GB	Needs 144 GB
DeepSeek R1 671B About 406 GB	Needs 406 GB	Needs 406 GB

Which should you get?

The RTX 5090, for speed. They fit the same models. Price matters as much as either number: check used prices on the builds page, where every parts list has a measured or estimated speed.

How we estimate

Both columns use the same formula: memory bandwidth divided by the weights read per token, calibrated on our own rack, with Ollama's default 4-bit sizes. Real results are usually within about a third. Measured either one? Send us the number.

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