Performance comparison: which is faster?
Core i5-12400 (Intel, 2022) and Core i9-9900 (Intel, 2019) are compared here. Compare not only scores, but also whether the motherboard can be reused and which GPU class is balanced with each CPU.
Overall performance: i5-12400 is about 2.6% faster
The sockets differ (LGA1700 / LGA1151), so switching requires a motherboard replacement. For games, performance balance with the GPU (guideline CPU:GPU = 0.9:1) matters more than CPU speed alone.
Relative performance score (higher is faster). Actual speed varies by workload, cooling, and memory configuration.
| Item | i5-12400 | i9-9900 |
|---|---|---|
| Performance Score | 19,500 | 19,000 |
| Generation | 12th Gen | 9th Gen |
| Socket | LGA1700 | LGA1151 |
| Release Year | 2022 | 2019 |
| Type | Desktop | Desktop |
| Compatible GPU Example | GeForce RTX 5060 | GeForce RTX 5060 |
| If You Want To... | Recommended |
|---|---|
| Prioritize maximum speed for heavy work or a high-end GPU | i5-12400 |
| Upgrade while reusing the current motherboard | Choose the CPU matching your motherboard socket |
| Prioritize value and adequate performance | i9-9900 (the lower model is often sufficient) |
i5-12400 is about 2.6% higher by score (i5-12400: 19500 points / i9-9900: 19000 points). For gaming, the GPU tier usually matters more than a few percent of CPU difference. For CPU-heavy work such as video editing and streaming, choose the faster CPU.
i5-12400 is 12th Gen, while i9-9900 is 9th Gen.The sockets differ (LGA1700 / LGA1151), so switching requires a motherboard replacement.
Using our CPU:GPU = 0.9:1 guideline, GeForce RTX 5060 pairs well with i5-12400 and GeForce RTX 5060 pairs well with i9-9900. If either GPU is too strong or too weak, one part holds the other back.
