direct comparison under identical conditions
RTX 3090 vs RTX 5090 local LLM performance and electricity rate comparison
If cost-effectiveness is a priority within 24GB, the 3090 is advantageous, and if 27B speed and 32GB storage space are important, the 5090 is advantageous.
core difference
| Measure | RTX 3090 24GB | RTX 5090 32GB |
|---|---|---|
| Available fast memory | 22.5GB | 30.5GB |
| Memory bandwidth | 936GB/s | 1792GB/s |
| Sustained LLM power | about 420W | about 620W |
| Korean price range (KRW) | 165–220 × KRW 10,000 | 620–780 × KRW 10,000 |
Which device suits the task?
| purpose | superior equipment | reason |
|---|---|---|
| Chat / coding | RTX 5090 32GB | In token generation with the same model, the side with higher memory bandwidth has an advantage. |
| Documents / RAG | RTX 5090 32GB | The side with larger available memory provides more headroom for longer contexts and KV cache. |
| Image / video | Similar | Let's look at generation tool compatibility and available GPU memory together. |
| Setup | Similar | Compare finished product status and initial driver·system configuration burden. |
| Power / space | RTX 3090 24GB | Prioritize the side with lower sustained power load. |
Local pricing
RTX 3090 24GB is approximately 5.08 million KRW cheaper than the mid-range price. Check both perceived speed and task-specific performance.