AMD Ryzen 9 3900X vs Intel Core i5-8400
37.6Single-core31.1
54.2Multi-core28.6
78.3Gaming27.2
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 gaming (+51) and Multi-core (+26). 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
- Stronger gaming score: 78 vs 27
- 611% higher L3 cache: 64 MB vs 9 MB
- 300% higher threads: 24 vs 6
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%Top 63% | 1,370Top 75% |
| Geekbench 6 (multi) | 11,000+124%Top 35% | 4,900Top 78% |
| Cinebench R23 (single) | 1,300+13%Top 59% | 1,150Top 75% |
| Cinebench R23 (multi) | 18,300+186%Top 24% | 6,400Top 77% |
| PassMark | 32,600+254%Top 26% | 9,200Top 80% |
Related comparisons
AMD Ryzen 9 3900Xvs AMD Ryzen 7 5700X3DVSAMD Ryzen 9 3900Xvs AMD Ryzen 7 8700GVSAMD Ryzen 9 3900Xvs AMD Ryzen 7 5800XVSAMD Ryzen 9 3900Xvs Intel Core i5-12600KFVSIntel Core i5-8400vs Intel Core i7-5820KVSIntel Core i5-8400vs Intel Core i5-9400FVSIntel Core i5-8400vs Intel Core i7-5930KVSIntel Core i5-8400vs Intel Core i7-7700KVS