AMD Ryzen 5 8400F vs AMD Ryzen 9 5900HX Comparison

The AMD Ryzen 5 8400F and AMD Ryzen 9 5900HX present a fascinating generational clash: a modern 6-core desktop part against an older 8-core mobile flagship. The benchmark data reveals a clear split between raw multi-threaded throughput and modern single-core efficiency, with the 8400F winning 14 of 21 head-to-head tests against the 5900HX's 7 wins.

Head-to-Head Benchmarks

The most decisive victory for the Ryzen 5 8400F comes in Cinebench R23 multi-core, where it scores 20,851 against the 5900HX's 12,845 — a massive 62.3% advantage. This is a stunning result given the 5900HX has two more cores and four more threads. The single-core gap is even more pronounced: the 8400F's 2,943 score in Cinebench R23 single-core is 97.8% higher than the 5900HX's 1,488, nearly doubling the older chip's output.

The 8400F also dominates in Cinebench R15 single-core with a 23.3% lead (296 vs 240), and in PassMark physics, where it posts 1,332 against the 5900HX's 909 — a 46.5% advantage. The newer chip's efficiency in prime number finding is striking: 89 vs 53, a 67.9% improvement. PassMark multi-thread also favors the 8400F (24,389 vs 22,326, a 9.2% win), despite the core deficit.

However, the 5900HX fights back in several areas. Its biggest win is in PassMark integer math, scoring 86,735 vs 74,021 — a 14.7% lead. It also wins 3DMark 16-thread (6,490 vs 6,091, a 6.1% margin) and 3DMark max-threads (6,487 vs 6,165, a 5% edge). The 5900HX takes PassMark data encryption (18,188 vs 16,646, an 8.5% lead) and floating-point math (47,556 vs 46,217, a 2.8% win). The 3DMark 8-thread test goes to the 5900HX narrowly (5,406 vs 5,275, a 2.4% margin), and Cinebench R15 multi-core is essentially a tie (2,106 vs 2,101, a 0.2% difference).

Low-thread tests tell a different story. The 8400F wins 3DMark 2-thread by 9% (1,874 vs 1,720) and 3DMark 4-thread by 8.5% (3,563 vs 3,285). PassMark single-thread goes to the 8400F by 16% (3,685 vs 3,178), and random string sorting favors it by 15.2% (34,604 vs 30,042). The 8400F also takes extended instructions (22,175 vs 19,488, a 13.8% win) and data compression by a hair (288,158 vs 287,793, a 0.1% margin).

Architecture Differences

These results stem from fundamentally different designs. The 8400F uses Zen 4 architecture on a 4 nm TSMC process, while the 5900HX uses Zen 3 on a 7 nm node. The transistor counts reflect this: the 8400F packs 25,000 million transistors on a 178 mm² die, compared to 10,700 million on the 5900HX's 180 mm² die. Both share 64 KB of L1 per core and 16 MB of shared L3, but the L2 differs: the 8400F has 1 MB per core versus 512 KB per core on the 5900HX.

Clock speeds favor the newer chip. The 8400F has a 4.20 GHz base and 4.70 GHz boost, while the 5900HX runs at 3.30 GHz base and 4.60 GHz boost. Power envelopes are inverted from what one might expect: the desktop 8400F has a 65 W TDP, while the mobile 5900HX is rated at 45 W. The 8400F supports DDR5 memory with 83.2 GB/s bandwidth; the 5900HX uses DDR4 with 68.3 GB/s. PCIe also differs: the 8400F has Gen 4 with 20 lanes (CPU only), while the 5900HX has Gen 3. The 5900HX includes Radeon Vega 8 integrated graphics, while the 8400F has N/A for iGPU. Both are socket-specific: AM5 for the 8400F, FP6 for the 5900HX.

The Verdict

The data strongly favors the Ryzen 5 8400F for most workloads. Its 62.3% lead in Cinebench R23 multi-core and 97.8% lead in single-core are not incremental gains; they represent a generational leap. The 8400F's average benchmark score is 25,005 versus 24,822 for the 5900HX, and both sit at the 77th percentile among all CPUs. The 8400F's nearest rivals include the Ryzen 5 7500F (0.2% ahead) and Intel Core i7-13620H (0.4% ahead), while the 5900HX sits near the Intel Core 5 210H (0.2% behind) and Ryzen 5 7600X3D (0.4% behind).

The 5900HX remains competitive in integer-heavy and encryption tasks, where its extra two cores provide a real advantage. Its 14.7% lead in integer math and 8.5% lead in encryption suggest workloads that scale with core count and benefit from the older architecture's integer throughput. However, the 8400F's dominance in modern benchmarks like Cinebench R23 and its 16% single-thread lead make it the better all-around choice for most users.

FAQ

Q: Which CPU has a higher single-threaded performance?

A: The Ryzen 5 8400F wins every single-thread test: 3DMark single-thread (951 vs 881, a 7.9% lead), Cinebench R23 single-core (2,943 vs 1,488, a 97.8% lead), and PassMark single-thread (3,685 vs 3,178, a 16% lead).

Q: How does the 5900HX's extra core count affect multi-threaded results?

A: The 5900HX wins 3DMark 16-thread (6,490 vs 6,091) and max-threads (6,487 vs 6,165), but the 8400F still wins Cinebench R23 multi-core by 62.3% (20,851 vs 12,845) and PassMark multi-thread by 9.2% (24,389 vs 22,326).

Q: What is the biggest performance gap between these two CPUs?

A: The largest delta is in Cinebench R23 single-core, where the 8400F scores 2,943 versus 1,488 — a 97.8% advantage. The next biggest is Cinebench R23 multi-core at 62.3%.

Q: Which CPU has better memory bandwidth?

A: The 8400F supports DDR5 with 83.2 GB/s bandwidth, while the 5900HX uses DDR4 with 68.3 GB/s. Both use dual-channel memory buses.

Q: Are these CPUs similar in overall benchmark averages?

A: Yes, the 8400F has an average benchmark score of 25,005 versus 24,822 for the 5900HX, a difference of only 0.7%. Both are at the 77th percentile.

Q: Does the 5900HX have integrated graphics?

A: Yes, it includes Radeon Vega 8. The 8400F has no integrated graphics (N/A).

Where Each One Wins

The Ryzen 5 8400F wins in single-thread sensitivity, modern rendering, and physics-based workloads. Its 97.8% lead in Cinebench R23 single-core makes it ideal for applications that rely on per-core performance, such as legacy software, spreadsheet calculations, and scripting. The 46.5% advantage in PassMark physics suggests better game physics simulation. The 67.9% lead in prime number finding points to superior integer-per-clock efficiency. For content creation using Cinebench, the 62.3% multi-core lead makes it the clear choice, as does its 15.2% win in random string sorting for data manipulation tasks.

The Ryzen 9 5900HX wins in raw integer throughput and encryption. Its 14.7% lead in PassMark integer math and 8.5% lead in data encryption indicate advantages in cryptography, compression algorithms, and heavy integer arithmetic. The 3DMark 16-thread and max-thread wins (6.1% and 5%) suggest better scaling in some synthetic 3D workloads. The 2.8% win in floating-point math is modest but real. For users running parallel integer-heavy workloads, the 5900HX's extra cores provide measurable benefits despite its older architecture.

Specification Differences

| Specification | Ryzen 5 8400F | Ryzen 9 5900HX |

|---|---|---|

| Cores | 6 | 8 |

| Threads | 12 | 16 |

| Base Clock | 4.20 GHz | 3.30 GHz |

| Boost Clock | 4.70 GHz | 4.60 GHz |

| TDP | 65 W | 45 W |

| Socket | AMD Socket AM5 | AMD Socket FP6 |

| Architecture | Zen 4 | Zen 3 |

| Codename | Phoenix | Cezanne |

| Process Node | 4 nm | 7 nm |

| Transistors | 25,000 million | 10,700 million |

| Die Size | 178 mm² | 180 mm² |

| L2 Cache | 1 MB (per core) | 512 KB (per core) |

| Memory Support | DDR5 | DDR4 |

| Memory Bandwidth | 83.2 GB/s | 68.3 GB/s |

| PCIe | Gen 4, 20 Lanes (CPU only) | Gen 3 |

| Integrated Graphics | N/A | Radeon Vega 8 |

| Market Segment | Desktop | Mobile |

| Release Date | 2024-03-31 | 2021-01-11 |

| Launch MSRP | $170 | null |