What is the biggest model the RX 6600 can run?

Qwen3 8B, which needs about 7 GB, on the 8 GB version at about 24 tok/s.

What is the biggest model the RX 6600 XT can run?

Qwen3 8B, which needs about 7 GB, on the 8 GB version at about 27 tok/s.

RX 6600 vs RX 6600 XT for local AI

Q: Which is better for local AI, the RX 6600 or the RX 6600 XT?

The RX 6600 XT, for speed. They fit the same models. Both fit the same models we track, up to Qwen3 8B. The RX 6600 XT generates about 14% faster on any model both can run, because it has 256 GB/s of memory bandwidth to the RX 6600's 224 GB/s.

Both fit the same models we track, up to Qwen3 8B. The RX 6600 XT generates about 14% faster on any model both can run, because it has 256 GB/s of memory bandwidth to the RX 6600's 224 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.

	RX 6600	RX 6600 XT
Memory	8 GB VRAM	8 GB VRAM
Bandwidth	224 GB/s	256 GB/s
Biggest model that fits	Qwen3 8B	Qwen3 8B
Best everyday pick	Qwen3 8B, ~24 tok/s	Qwen3 8B, ~27 tok/s

Model by model

Every model, side by side

Estimated generation speed at the largest memory size each was sold in (8 GB and 8 GB).

Model	RX 6600	RX 6600 XT
Qwen3 4B About 4 GB	~49 tok/s Runs great	~56 tok/s Runs great
Qwen3 8B About 7 GB	~24 tok/s Usable	~27 tok/s Usable
Gemma 3 12B About 10 GB	Needs 10 GB	Needs 10 GB
Qwen3 14B About 11 GB	Needs 11 GB	Needs 11 GB
gpt-oss 20B About 16 GB	Needs 16 GB	Needs 16 GB
Gemma 3 27B About 19 GB	Needs 19 GB	Needs 19 GB
Qwen3 30B-A3B About 21 GB	Needs 21 GB	Needs 21 GB
Qwen3 32B About 22 GB	Needs 22 GB	Needs 22 GB
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 RX 6600 XT, 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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Other matchups

Every comparison