Best local AI models for AMD RX 6600S
4 GB GDDR6. At a 4k context, 81 of the 233 models in our catalog with verified parameter counts fit fully, up to Lumina-Next / Lumina-Image 2.0 at 5B parameters.
Check your own machine against every model →The largest models that fit fully
The 30 largest of the 81 models that fit; every smaller model in the catalog fits too. Best quant means the highest quality compression whose weights and 4k context both sit inside the memory.
| Model | Parameters | Best quant that fits | Memory used at 4k |
|---|---|---|---|
| Lumina-Next / Lumina-Image 2.0 | 5B | Q4_K_M | 3.7 GB |
| CogVideoX 2B / 5B | 5B | Q4_K_M | 3.7 GB |
| DeepSeek-VL2 | 4.5B | Q5_K_M | 3.8 GB |
| DeepFloyd IF | 4.3B | Q5_K_M | 3.7 GB |
| Phi-3.5-vision | 4.2B | Q5_K_M | 3.6 GB |
| Qwen3 4B | 4B | Q6_K | 3.9 GB |
| Gemma 3 4B | 4B | Q6_K | 3.9 GB |
| Gemma 4 E4B | 4B | Q6_K | 3.9 GB |
| MiniCPM 3 4B | 4B | Q6_K | 3.9 GB |
| Danube 3 4B | 4B | Q6_K | 3.9 GB |
| Fish Speech 1.5 / OpenAudio S1 | 4B | Q6_K | 3.9 GB |
| Phi-4-mini-instruct | 3.8B | Q6_K | 3.7 GB |
| Phi-3.5 Mini | 3.8B | Q6_K | 3.7 GB |
| OmniGen / OmniGen2 | 3.8B | Q6_K | 3.7 GB |
| SD Cascade (Würstchen v3) | 3.6B | Q6_K | 3.5 GB |
| SDXL Turbo | 3.5B | Q6_K | 3.4 GB |
| SDXL Lightning | 3.5B | Q6_K | 3.4 GB |
| ACE-Step | 3.5B | Q6_K | 3.4 GB |
| MusicGen small/medium/large | 3.3B | Q6_K | 3.2 GB |
| SmolLM3 3B | 3B | Q8_0 | 3.8 GB |
| Replit Code v1.5 3B | 3B | Q8_0 | 3.8 GB |
| Kandinsky 3.1 | 3B | Q8_0 | 3.8 GB |
| Voxtral Mini / Small | 3B | Q8_0 | 3.8 GB |
| Orpheus TTS | 3B | Q8_0 | 3.8 GB |
| Higgs Audio v2 | 3B | Q8_0 | 3.8 GB |
| Allegro | 2.8B | Q8_0 | 3.6 GB |
| Open-Sora Plan | 2.7B | Q8_0 | 3.4 GB |
| LFM2 1.2B / 2.6B | 2.6B | Q8_0 | 3.3 GB |
| Playground v2.5 | 2.6B | Q8_0 | 3.3 GB |
| Stable Diffusion 3.5 Medium | 2.5B | Q8_0 | 3.2 GB |
Close, but only with CPU offload
These need more than the card holds at their smallest practical quant, so part of the model runs from system memory (figures assume 32 GB of it). They work, several times slower.
| Model | Parameters | Memory at FP8 / optimized | System RAM at 4k |
|---|---|---|---|
| Stable Diffusion XL | 3.417B | 4.1 GB needed | 6.1 GB |
| Phi-3 Mini | 3.8B | 4.4 GB needed | 6.4 GB |
| Phi-4-multimodal | 5.6B | 4.1 GB needed | 6.1 GB |
| Magicoder-S-DS 6.7B | 6.7B | 4.9 GB needed | 6.9 GB |
| Mistral 7B | 7B | 5.7 GB needed | 7.7 GB |
| Qwen2.5 0.5B / 1.5B / 3B / 7B | 7B | 5.1 GB needed | 7.1 GB |
| OLMo 2 1B / 7B | 7B | 5.1 GB needed | 7.1 GB |
| Falcon 3 1B / 3B / 7B | 7B | 5.1 GB needed | 7.1 GB |
| Command R7B | 7B | 5.1 GB needed | 7.1 GB |
| OpenHermes 2.5 | 7B | 5.1 GB needed | 7.1 GB |
How to read this
The AMD Radeon RX 6600S is a mobile graphics card equipped with 4 GB of GDDR6 video memory. This dedicated memory pool determines which artificial intelligence models you can run entirely on your hardware. When a model fits completely within your video memory, it processes tokens and generates outputs at maximum speed. If a model exceeds this limit, you must use alternative execution strategies.
The quantization column indicates the compression level applied to each model. Quantization reduces the precision of model weights to save space. For example, the Q6_K quant represents a high quality compression level that preserves most of the original model intelligence. The Q8_0 quant offers even higher fidelity but requires more memory. Choosing the correct quant allows you to run capable models like Phi-4-mini-instruct or Qwen3 4B within your hardware limits.
To run larger models, you can offload a portion of the workload to your system memory. This process requires a system with sufficient RAM, such as 32 GB of system RAM. Offloading allows you to load models that exceed 4 GB, but it introduces a performance cost. Because system RAM is much slower than GDDR6 video memory, your generation speeds will decrease significantly when offloading.
Several high quality models fit directly into your video memory without offloading. Lumina-Next and CogVideoX 5B run at the Q4_K_M quant using 3.7 GB of memory. DeepSeek-VL2 fits at the Q5_K_M quant using 3.8 GB of memory. For text generation, Gemma 3 4B and MiniCPM 3 4B utilize 3.9 GB of memory at the Q6_K quant. Image generation models like SDXL Turbo fit within 3.4 GB of memory at the Q6_K quant.
If you choose to offload, you can access larger architectures. Mistral 7B requires 5.7 GB at the Q4_K_M quant and needs 7.7 GB of system RAM. Qwen2.5 7B and Falcon 3 7B require 5.1 GB at the Q4_K_M quant and need 7.1 GB of system RAM. These larger models provide better reasoning capabilities at the expense of generation speed.
Keep in mind that memory consumption estimates assume a standard 4k context window. As your conversation history grows, the context window consumes additional video memory. If you generate very long responses or maintain long chat sessions, the model might exceed your 4 GB limit and trigger automatic system RAM offloading.