NVIDIA RTX 4090 vs AMD Radeon RX 6950 XT
Which graphics card is better for running local language models? Here is how the NVIDIA RTX 4090 (24 GB) compares against the AMD Radeon RX 6950 XT (16 GB) in real memory headroom, supported model architectures, and generation speed.
NVIDIA · Ada Lovelace
24 GB VRAM
NVIDIA RTX 4090
- Memory Bandwidth: 1008 GB/s (GDDR6X 384-bit)
- Fits fully in VRAM: 36 popular models
- Power Draw (TDP): 450W
- Largest recommended (Q4): 32B–34B
AMD · Desktop
16 GB VRAM
AMD Radeon RX 6950 XT
- Memory Bandwidth: 512 GB/s (GDDR6)
- Fits fully in VRAM: 34 popular models
- Power Draw (TDP): 150W
- Largest recommended (Q4): 20B–22B
The AI Local Check Verdict: Which GPU should you buy for AI?
The NVIDIA RTX 4090 is the clear winner for local AI. It provides both 8 GB more VRAM and higher memory bandwidth (1008 GB/s vs 512 GB/s).
This allows it to run larger model architectures entirely in video memory while also delivering faster token generation speeds on models of all sizes.
Models that fit on NVIDIA RTX 4090, but NOT on AMD Radeon RX 6950 XT
These models run entirely in GPU VRAM on the NVIDIA RTX 4090, but require slow system RAM offload on the AMD Radeon RX 6950 XT:
| Model | Size | Downloads | NVIDIA RTX 4090 | AMD Radeon RX 6950 XT |
|---|---|---|---|---|
| ggml-org/NVIDIA-Nemotron-3.5-Lightning-30B-A3B-GGUF | 31.58B | 249,888 | Fits in VRAM | Offload (Slow) |
| unsloth/Qwen3-Coder-Next-GGUF | 79.67B | 169,899 | Fits in VRAM | Offload (Slow) |
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