AMD Ryzen 9 3900X vs Intel Core i5-8400
37.6Single-core31.1
54.2Multi-core28.6
78.3Gamingspec-based27.2
18 spec wins — AMD Ryzen 9 3900X1 spec wins — Intel Core i5-8400
InnoReviews verdict
AMD Ryzen 9 3900X wins this desktop processor face-off, 55.3 to 29, pulling ahead mainly in multi-core (+26) and single-core (+7). Intel Core i5-8400 still makes sense if its price or standout specs fit your needs better.
Which would you pick?
Key differences
Reasons to pick the AMD Ryzen 9 3900X
- Stronger single-core score: 38 vs 31
- Stronger multi-core score: 54 vs 29
- 611% higher L3 cache: 64 MB vs 9 MB
- 300% higher threads: 24 vs 6
- 300% higher L2 cache: 6 MB vs 2 MB
Reasons to pick the Intel Core i5-8400
- 38% lower Base TDP: 65 W vs 105 W
- Lower launch price: $182 vs $499
General
| Spec | AMD Ryzen 9 3900X | Intel Core i5-8400 |
|---|---|---|
| Announced | 2019 | 2017 |
| Socket | AM4 | LGA1151-v2 |
| Process | 7 nm+50% | 14 nm |
| Base TDP | 105 W | 65 W+38% |
| Max turbo power | 142 W | — |
| Unlocked multiplier | Yes | No |
| Cooler included | Yes | Yes |
Cores & Clocks
| Spec | AMD Ryzen 9 3900X | Intel Core i5-8400 |
|---|---|---|
| Cores | 12+100% | 6 |
| Performance cores | 12+100% | 6 |
| Efficiency cores | 0 | 0 |
| Threads | 24+300% | 6 |
| Base clock | 3.8 GHz+36% | 2.8 GHz |
| Boost clock | 4.6 GHz+15% | 4 GHz |
| L2 cache | 6 MB+300% | 2 MB |
| L3 cache | 64 MB+611% | 9 MB |
Integrated GPU
| Spec | AMD Ryzen 9 3900X | Intel Core i5-8400 |
|---|---|---|
| iGPU | — | Intel UHD Graphics 630 |
| iGPU clock | — | 1,050 MHz |
Memory
| Spec | AMD Ryzen 9 3900X | Intel Core i5-8400 |
|---|---|---|
| Memory support | DDR4-3200 | DDR4-2666 |
| Max memory | 128 GB+100% | 64 GB |
| Memory channels | 2 | 2 |
Platform
| Spec | AMD Ryzen 9 3900X | Intel Core i5-8400 |
|---|---|---|
| PCIe version | 4+33% | 3 |
| CPU PCIe lanes | 24+50% | 16 |
Benchmarks
| Spec | AMD Ryzen 9 3900X | Intel Core i5-8400 |
|---|---|---|
| Geekbench 6 (single) | 1,540+12%Bottom 32% | 1,370Bottom 22% |
| Geekbench 6 (multi) | 11,000+124%Top 47% | 4,900Bottom 19% |
| Cinebench R23 (single) | 1,300+13%Bottom 33% | 1,150Bottom 22% |
| Cinebench R23 (multi) | 18,300+186%Top 32% | 6,400Bottom 19% |
| PassMark | 32,600+254%Top 37% | 9,200Bottom 14% |
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