AMD Ryzen 9 9900X vs AMD Ryzen AI 9 HX 375 Comparison

AMD Ryzen 9 9900X and AMD Ryzen AI 9 HX 375 are both 12-core, 24-thread Zen 5 processors from AMD, but they serve entirely different market segments. The 9900X is a desktop part built for maximum throughput, while the HX 375 is a low-power mobile chip designed for laptops. The database contains 17 head-to-head benchmark comparisons between them, and the 9900X wins all 17. This analysis examines where each processor excels, the architectural differences that drive their performance, and what the recorded data says about choosing between them.

Where Each One Wins

The benchmark data is unambiguous: the AMD Ryzen 9 9900X wins every single recorded head-to-head test. Out of 17 comparisons, the desktop chip takes 17 victories and the Ryzen AI 9 HX 375 takes zero. This is not a close contest by any measure. The 9900X dominates across single-threaded, multi-threaded, and specialized workload tests.

The Ryzen AI 9 HX 375 does not win any category in the database. Its strengths lie outside the recorded benchmark suite, specifically in its 28 W TDP and mobile form factor. The data shows no workload where the HX 375 outperforms the 9900X, so the choice between them comes down to platform and power constraints rather than raw performance.

For desktop users building a high-performance rig, the 9900X is the clear performer. It delivers higher scores in every recorded test, from Cinebench rendering to PassMark math and encryption workloads. For laptop buyers, the HX 375 is the only one of the two that fits a mobile chassis, and its performance is still strong for a 28 W part, landing in the 89th percentile of all CPUs in the database.

The 9900X sits in the 92nd percentile of all CPUs, with an average benchmark score of 57,498. The HX 375 sits in the 89th percentile with an average score of 46,030. The 11,468 point gap in average score represents a meaningful difference in overall compute capability.

Architecture Differences

Both processors use the Zen 5 architecture and are built on TSMC's 4 nm process node. The similarities end there. The 9900X uses the Granite Ridge codename and belongs to the Ryzen 9 generation of the 9000 series. The HX 375 uses the Strix Point codename and belongs to the Ryzen AI 300 generation, which combines Zen 5 and Zen 5c cores.

The desktop chip features a dual-chiplet design with a die size of 2x 70.6 mm² and 16,630 million transistors. The mobile chip uses a monolithic design with a 233 mm² die, and its transistor count is not recorded in the database. This difference in physical design has direct implications for power efficiency and thermals.

Cache configuration differs substantially. Both chips have 80 KB of L1 cache per core and 1 MB of L2 cache per core. The L3 cache is where they diverge: the 9900X has 64 MB of L3 cache, while the HX 375 has only 16 MB. That 48 MB difference explains much of the performance gap in cache-sensitive workloads like data compression and random string sorting.

Memory support also differs. The 9900X supports DDR5 memory with dual-channel access and 89.6 GB/s of bandwidth, plus ECC memory support. The HX 375 supports both DDR5 and LPDDR5X, also dual-channel with the same 89.6 GB/s bandwidth, but it lacks ECC support. The mobile chip's support for LPDDR5X is notable for laptops, where lower-power memory is common.

PCIe connectivity is another major divider. The 9900X offers PCIe Gen 5 with 24 lanes from the CPU. The HX 375 offers PCIe Gen 4 with 16 lanes. This makes the desktop chip substantially more capable for high-bandwidth expansion cards, NVMe storage, and GPUs.

The integrated graphics differ as well. The 9900X includes Radeon Graphics, while the HX 375 includes the Radeon 890M. The database does not include graphics benchmarks, so no direct comparison is possible from the recorded data.

The 9900X has an unlocked multiplier and a launch MSRP of $499. The HX 375 has a locked multiplier and no recorded launch MSRP. The desktop chip uses Socket AM5, while the mobile chip uses Socket FP8.

Clock speeds show the desktop advantage. The 9900X has a 4.40 GHz base clock and a 5.60 GHz boost clock. The HX 375 has a 2.00 GHz base clock and a 5.10 GHz boost clock. The desktop chip runs 2.40 GHz faster at base and 0.50 GHz faster at boost.

Power targets differ by a wide margin. The 9900X has a 120 W TDP, while the HX 375 has a 28 W TDP. The mobile chip delivers a large fraction of the desktop chip's performance at less than a quarter of the power envelope, which is the core value proposition for the HX 375.

Head-to-Head Benchmarks

The largest single victory for the 9900X comes in PassMark find prime numbers, where it scores 436 against the HX 375's 122. That is a 257.4 percent advantage, the only test in the database where the desktop chip more than triples the mobile chip's score.

In PassMark extended instructions, the 9900X scores 55,243 against 29,269, a difference of 88.7 percent. This test measures SIMD and vectorized workload performance, where the desktop chip's higher clocks and larger cache pay off significantly.

PassMark physics shows an 85.9 percent gap, with the 9900X scoring 3,381 versus 1,819. Physics simulation tends to scale with core count and memory bandwidth, both areas where the desktop chip has an advantage.

Geekbench multicore shows a 58.9 percent lead for the 9900X, scoring 22,174 versus 13,957. The single-core Geekbench test shows a 44.4 percent gap, with scores of 3,010 and 2,084. The single-core gap is particularly telling because both chips use the same Zen 5 architecture and the same 4 nm process, so the difference comes down to clock speed and cache size.

Cinebench R23 multicore shows the 9900X scoring 32,172 against 21,812, a 47.5 percent difference. Cinebench R15 multicore shows a 50.2 percent gap, with scores of 5,008 and 3,334. Cinebench R23 single-core shows a 13.3 percent gap, with scores of 2,253 and 1,988. Cinebench R15 single-core shows a 17.3 percent gap, with scores of 353 and 301.

PassMark data compression shows a 68.8 percent advantage for the 9900X, scoring 683,579 versus 404,918. Data encryption shows a 60.7 percent gap, with scores of 33,421 and 20,802. Floating point math shows a 59.8 percent gap, with scores of 120,083 and 75,153. Integer math shows a 48.7 percent gap, with scores of 181,056 and 121,754.

PassMark multithread shows a 66 percent gap, with the 9900X scoring 54,643 versus 32,916. Random string sorting shows a 61.6 percent gap, with scores of 72,013 and 44,552. PassMark single-thread shows a 20.8 percent gap, with scores of 4,672 and 3,867.

The 3DMark tests in the database only include results for the 9900X, so no comparison is possible for those workloads. The desktop chip records scores of 12,552 in 16-thread, 2,519 in 2-thread, 4,886 in 4-thread, 9,114 in 8-thread, 13,929 in max-thread, and 1,286 in single-thread. No corresponding HX 375 scores are recorded.

The pattern across all head-to-head tests is consistent: the 9900X leads by double-digit percentages in every category, with the gap ranging from 13.3 percent in Cinebench R23 single-core to 257.4 percent in PassMark find prime numbers.

The Verdict

The data supports a straightforward conclusion. The AMD Ryzen 9 9900X is the faster processor in every recorded benchmark, with wins in all 17 head-to-head tests. It delivers higher single-core performance, higher multi-core performance, and higher specialized workload performance across the board.

The Ryzen AI 9 HX 375 is not competitive with the 9900X in raw performance, but it is not meant to be. It is a 28 W mobile processor designed for laptops, while the 9900X is a 120 W desktop processor designed for full-size systems. The mobile chip still ranks in the 89th percentile of all CPUs, which makes it a strong performer for its class.

Buyers who need maximum compute performance and are building a desktop system should choose the 9900X. The data shows it outperforms the HX 375 by margins ranging from 13.3 percent to 257.4 percent depending on the workload. The desktop chip also offers PCIe Gen 5 with 24 lanes, ECC memory support, an unlocked multiplier, and 64 MB of L3 cache, all of which are absent from the mobile part.

Buyers who need a processor for a laptop should choose the HX 375, because the 9900X uses Socket AM5 and has no mobile variant in the database. The HX 375 delivers respectable performance in a 28 W envelope, with support for DDR5 and LPDDR5X memory and an integrated Radeon 890M GPU. Its locked multiplier and PCIe Gen 4 connectivity are typical for mobile processors.

The nearest rivals in the database put both chips in context. The 9900X scores within 0.1 percent of the AMD EPYC 9015, within 0.2 percent of the AMD EPYC 7313, 1.1 percent behind the Intel Core i9-14900, and 1.4 percent behind the Intel Xeon Platinum 8260M. The HX 375 scores within 0.1 percent of the Intel Core Ultra 5 235, within 0.1 percent of the Intel Core i9-13900HX, 0.1 percent ahead of the AMD EPYC 4364P, and 0.2 percent ahead of the AMD EPYC 7303.

FAQ

Q: Which processor has more cores?

A: Both have 12 cores and 24 threads. Core count is identical.

Q: How much faster is the Ryzen 9 9900X in Cinebench R23 multi-core?

A: The 9900X scores 32,172 versus 21,812 for the HX 375, a 47.5 percent advantage.

Q: What is the TDP difference between the two?

A: The 9900X has a 120 W TDP, while the HX 375 has a 28 W TDP. The mobile chip uses 92 W less power.

Q: Do both processors support ECC memory?

A: No. The 9900X supports ECC memory, while the HX 375 does not.

Q: What socket does each processor use?

A: The 9900X uses AMD Socket AM5, and the HX 375 uses AMD Socket FP8.

Q: Which processor has a higher boost clock?

A: The 9900X boosts to 5.60 GHz, while the HX 375 boosts to 5.10 GHz.

Q: How much L3 cache does each processor have?

A: The 9900X has 64 MB of L3 cache, while the HX 375 has 16 MB.

Specification Differences

| Specification | AMD Ryzen 9 9900X | AMD Ryzen AI 9 HX 375 |

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

| Cores | 12 | 12 |

| Threads | 24 | 24 |

| Base clock | 4.40 GHz | 2.00 GHz |

| Boost clock | 5.60 GHz | 5.10 GHz |

| TDP | 120 W | 28 W |

| Socket | AMD Socket AM5 | AMD Socket FP8 |

| Codename | Granite Ridge | Strix Point |

| Generation | Ryzen 9 (Zen 5) | Ryzen AI 300 (Zen 5 / Zen 5c) |

| Process node | 4 nm | 4 nm |

| Die size | 2x 70.6 mm² | 233 mm² |

| Transistors | 16,630 million | Not recorded |

| L1 cache | 80 KB per core | 80 KB per core |

| L2 cache | 1 MB per core | 1 MB per core |

| L3 cache | 64 MB | 16 MB |

| Memory support | DDR5 | DDR5, LPDDR5X |

| Memory bandwidth | 89.6 GB/s | 89.6 GB/s |

| ECC memory | Yes | No |

| PCIe | Gen 5, 24 lanes | Gen 4, 16 lanes |

| Integrated graphics | Radeon Graphics | Radeon 890M |

| Market segment | Desktop | Mobile |

| Multiplier unlocked | Yes | No |

| Launch MSRP | $499 | Not recorded |

| Part number | 100-000000662 | 100-000001682 |

| Release date | 2024-08-14 | 2024-06-30 |