AMD Ryzen 7 5800X vs AMD Ryzen 9 3900XT
- The AMD Ryzen 7 5800X launched $50 lower ($449 vs $499).
- Same socket (AM4): both fit the same motherboards, BIOS permitting.
- The AMD Ryzen 9 3900XT has 4 more cores (12 vs 8).
AMD Ryzen 7 5800X
8 cores · 4.7 GHz · AM4 · DDR4-3200
Launched at $449
AMD Ryzen 9 3900XT
12 cores · 4.7 GHz · AM4 · DDR4-3200
Launched at $499
Specs side by side
4 of 10 differ, marked. Speed isn't compared here: we only list specs we can source.
| Spec | AMD Ryzen 7 5800X | AMD Ryzen 9 3900XT |
|---|---|---|
| Cores | 8 cores, 16 threads | 12 cores, 24 threads |
| Boost clock | Up to 4.7 GHz | Up to 4.7 GHz |
| L3 cache | 32 MB | 64 MB |
| Power (TDP) | 105 W | 105 W |
| Built-in graphics | No | No |
| Socket | AM4 | AM4 |
| PCIe | PCIe 4.0 | PCIe 4.0 |
| Official DDR4 speed | DDR4-3200 (DDR4-2667 with 4 modules) | DDR4-3200 |
| Segment | Desktop | Desktop |
| Launched | Nov 5, 2020 | Jul 7, 2020 |
Which motherboards take them
AMD Ryzen 7 5800X
AM4 boards with these chipsets:
- X570
- B550 (may need a BIOS update)
- A520 (may need a BIOS update)
- X470 (may need a BIOS update)
- B450 (may need a BIOS update)
- X370 (may need a BIOS update)
- B350 (may need a BIOS update)
- A320 (may need a BIOS update)
- X300
- A300
AMD Ryzen 9 3900XT
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 5800X
- Wikipedia: List of AMD Ryzen processors · CC BY-SA 4.0
AMD Ryzen 9 3900XT
- 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.