Head to head · October 2026
RTX 3090 vs MI50 32GB: which is better for local AI?
24GB against 32GB, 936 against 1,024 GB/s. What each runs, how fast, and which one to buy.
The verdict
The MI50 32GB has 8GB more memory (32GB vs 24GB), so it runs larger models. The RTX 3090 generates text about 53% faster thanks to 936 GB/s of memory bandwidth versus 1,024 GB/s. The MI50 32GB costs about $450 less ($600 used vs $1,050 used).
- Get the RTX 3090 if speed matters most or you want the widest software support (CUDA).
- Get the MI50 32GB if you want to run bigger models or use longer context or you want the most for your money.
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Performance
Model by model
Estimated single-user generation speed for popular models, at the best quantization each card can hold with 8K context.
| Model | RTX 3090 | MI50 32GB |
|---|---|---|
| Llama 3.1 8B Instruct | ~73 tok/sQ8_0 | ~49 tok/sQ8_0 |
| Qwen3 14B | ~41 tok/sQ8_0 | ~28 tok/sQ8_0 |
| gpt-oss-20b | ~120 tok/sMXFP4 | ~74 tok/sMXFP4 |
| Qwen3 30B-A3B (2507) | ~135 tok/sQ4_K_M | ~67 tok/sQ6_K |
| Gemma 3 27B | ~39 tok/sQ4_K_M | ~20 tok/sQ6_K |
| Qwen3 32B | ~41 tok/sQ3_K_M | ~19 tok/sQ5_K_M |
| Llama 3.3 70B Instruct | ~1.8 tok/sQ4_K_M Partial offload | ~2.5 tok/sQ4_K_M Partial offload |
| gpt-oss-120b | ~21 tok/sMXFP4 Partial offload | ~22 tok/sMXFP4 Partial offload |
Estimates from our bandwidth model; see methodology. Measured results, where we have them, are on each GPU's page.
Specifications
Spec by spec
| Spec | RTX 3090 | MI50 32GB |
|---|---|---|
| Memory | 24GB GDDR6X | 32GB HBM2● |
| Bandwidth | 936 GB/s | 1,024 GB/s● |
| Power | 350W | 300W● |
| Price | ~$1,050 used | ~$600 used● |
| Price per GB | $44 | $19● |
| Architecture | Ampere | Vega 20 (GCN) |
| Released | 2020 | 2018 |
| Software | CUDA, Vulkan | ROCm, Vulkan |
Our take
Bottom line on each
The default value pick for 24GB of CUDA memory and the backbone of most multi-GPU builds.
Huge bandwidth per dollar on paper, but ROCm has dropped it and shortage pricing erased the bargain.
Frequently asked questions
Is the RTX 3090 or MI50 32GB better for running LLMs?
The MI50 32GB has 8GB more memory (32GB vs 24GB), so it runs larger models. The RTX 3090 generates text about 53% faster thanks to 936 GB/s of memory bandwidth versus 1,024 GB/s. The MI50 32GB costs about $450 less ($600 used vs $1,050 used).
How much faster is the RTX 3090 than the MI50 32GB for AI?
About 53% faster at generating text in our estimates, because token generation is limited by memory bandwidth (936 GB/s vs 1,024 GB/s). Prompt processing depends more on compute and can differ by more.
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