AMD Ryzen 7 1800X vs AMD Ryzen 9 3900X
- Both launched at $499.
- Same socket (AM4): both fit the same motherboards, BIOS permitting.
- The AMD Ryzen 9 3900X has 4 more cores (12 vs 8).
AMD Ryzen 7 1800X
8 cores · 4.1 GHz · AM4 · DDR4-2666
Launched at $499
AMD Ryzen 9 3900X
12 cores · 4.6 GHz · AM4 · DDR4-3200
Launched at $499
Specs side by side
7 of 10 differ, marked. Speed isn't compared here: we only list specs we can source.
| Spec | AMD Ryzen 7 1800X | AMD Ryzen 9 3900X |
|---|---|---|
| Cores | 8 cores, 16 threads | 12 cores, 24 threads |
| Boost clock | Up to 4.1 GHz | Up to 4.6 GHz |
| L3 cache | 16 MB | 64 MB |
| Power (TDP) | 95 W | 105 W |
| Built-in graphics | No | No |
| Socket | AM4 | AM4 |
| PCIe | PCIe 3.0 | PCIe 4.0 |
| Official DDR4 speed | DDR4-2666 | DDR4-3200 |
| Segment | Desktop | Desktop |
| Launched | March 2, 2017 | Jul 7, 2019 |
Which motherboards take them
AMD Ryzen 7 1800X
AM4 boards with these chipsets:
- X570
- B550 (may need a BIOS update)
- A520 (may need a BIOS update)
- X470
- B450
- X370
- B350
- A320
- X300
- A300
AMD Ryzen 9 3900X
AM4 boards with these chipsets:
- X570
- B550
- A520
- X470
- B450
- X370 (may need a BIOS update)
- B350 (may need a BIOS update)
- A320 (may need a BIOS update)
- X300
- A300
Outlined: those boards may need a BIOS update before the CPU works.
Sources
AMD Ryzen 7 1800X
- Wikipedia: List of AMD Ryzen processors · CC BY-SA 4.0
AMD Ryzen 9 3900X
- Wikipedia: List of AMD Ryzen processors · CC BY-SA 4.0
Specs last checked Oct 19, 2026. Spotted a mistake? Tell us and we'll fix it.