AMD Ryzen 9 5900 vs AMD Ryzen AI 9 HX PRO 375 Comparison

The AMD Ryzen AI 9 HX PRO 375 and AMD Ryzen 9 5900 are both 12-core, 24-thread processors, but they target completely different platforms and use cases. The HX PRO 375 is a modern mobile part built on Zen 5, while the 5900 is a desktop chip from the Zen 3 generation. The benchmark data shows a near-total dead heat in overall average score, with the 5900 edging ahead by just 0.4% (46971 vs 46773). However, that aggregate number hides a clear split: the older desktop chip wins 10 of 17 head-to-head tests, while the newer mobile chip wins 7, often by larger margins in specific workloads.

Where Each One Wins

The AMD Ryzen 9 5900 dominates in sustained multi-threaded rendering and classic compute tasks. It wins every single Cinebench test, from R15 multicore (2906 vs 2875) through R23 multicore (28834 vs 28529), with a consistent 1.1% advantage across the board. It also takes PassMark's integer math (128641 vs 120604, a 6.2% lead), data encryption (26247 vs 21311, a massive 18.8% lead), and prime number finding (213 vs 121, a 43.2% blowout). If your workload is heavy on traditional CPU arithmetic, encryption, or rendering, the 5900 is the clear choice.

The AMD Ryzen AI 9 HX PRO 375 wins in single-threaded PassMark tests and specialized instruction workloads. It beats the 5900 by 11.6% in PassMark single-thread (3839 vs 3439) and by 7.8% in extended instructions (28947 vs 26859). It also leads in floating-point math (74296 vs 69124, a 7.5% gain), physics simulation (1867 vs 1697, a 10% gain), and random string sorting (45628 vs 43386, a 5.2% gain). Data compression is a dead heat at 411610 vs 411453. The HX PRO 375 is the better part for tasks that leverage newer instruction sets, floating-point throughput, or single-thread responsiveness.

FAQ

Q: Which processor has a higher overall benchmark average?

A: The AMD Ryzen 9 5900 has a slightly higher average benchmark score of 46971, compared to 46773 for the Ryzen AI 9 HX PRO 375. This puts the 5900 at a 0.4% advantage and gives it a 93rd percentile ranking versus the HX PRO 375's 92nd percentile.

Q: Is the Ryzen AI 9 HX PRO 375 faster in single-core performance?

A: In Cinebench R23 single-core, the 5900 is ahead by 1.1% (4070 vs 4027). However, in PassMark's single-thread test, the HX PRO 375 wins decisively by 11.6% (3839 vs 3439). The result depends entirely on the benchmark methodology.

Q: How do they compare in encryption workloads?

A: The Ryzen 9 5900 is significantly faster in PassMark data encryption, scoring 26247 against the HX PRO 375's 21311. That is an 18.8% advantage for the desktop chip.

Q: Does the mobile chip win any Cinebench tests?

A: No. The Ryzen 9 5900 wins every Cinebench R15, R20, and R23 test, both single-core and multi-core, with margins of 1.1% to 1.2% in each case.

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

A: The largest difference is in PassMark's find prime numbers test, where the Ryzen 9 5900 scores 213 versus the HX PRO 375's 121, a 43.2% advantage for the 5900.

Q: Which chip has better floating-point performance?

A: The Ryzen AI 9 HX PRO 375 wins PassMark floating-point math with a score of 74296, beating the 5900's 69124 by 7.5%.

Head-to-Head Benchmarks

The Cinebench suite is a clean sweep for the AMD Ryzen 9 5900. In R15, it wins multicore 2906 to 2875 and single-core 410 to 405, both by 1.1% and 1.2% respectively. The R20 results are nearly identical in margin: multicore 12110 vs 11982 and single-core 1709 vs 1691, both at 1.1% for the 5900. R23 follows the pattern, with the 5900 taking multicore 28834 vs 28529 and single-core 4070 vs 4027, again a 1.1% gap. These are consistent, small margins that suggest the Zen 3 desktop chip has a slight but reliable edge in rendering workloads.

The PassMark results tell a different story. The HX PRO 375's biggest wins come in single-thread performance, where it scores 3839 to the 5900's 3439, a commanding 11.6% lead. It also wins extended instructions by 7.8% (28947 vs 26859) and floating-point math by 7.5% (74296 vs 69124). Physics simulation goes to the HX PRO 375 by 10% (1867 vs 1697), and random string sorting by 5.2% (45628 vs 43386). Data compression is effectively tied at 411610 vs 411453, a 0% delta.

The 5900's PassMark victories are led by the 43.2% margin in find prime numbers (213 vs 121) and the 18.8% lead in data encryption (26247 vs 21311). It also wins integer math by 6.2% (128641 vs 120604) and multithread by 1.2% (33969 vs 33564). The overall win count of 10-7 for the 5900 is heavily weighted by these specific integer and encryption workloads, while the HX PRO 375's wins are more concentrated in modern instruction handling and floating-point.

Specification Differences

The two chips diverge sharply on platform and memory. The Ryzen AI 9 HX PRO 375 uses AMD Socket FP8 and supports DDR5 and LPDDR5X memory with a bandwidth of 89.6 GB/s, while the Ryzen 9 5900 uses AMD Socket AM4 and is limited to DDR4 with 51.2 GB/s bandwidth. Both are dual-channel, and both support ECC memory.

Clock speeds favor the mobile chip. The HX PRO 375 has a base clock of 2000 MHz and a boost of 5.10 GHz, while the 5900 runs at a 3000 MHz base and 4.70 GHz boost. The 5900 has a much higher TDP of 65W versus 28W for the HX PRO 375, reflecting its desktop design. The HX PRO 375 includes integrated Radeon 890M graphics, while the 5900 has no integrated GPU. The 5900 has 20 PCIe Gen 4 lanes (CPU only) versus 16 for the HX PRO 375. The 5900 has an unlocked multiplier, while the HX PRO 375 is locked.

Architecture Differences

The fundamental architecture gap is generational. The Ryzen AI 9 HX PRO 375 is built on Zen 5 (Strix Point) using TSMC's 4 nm process with a die size of 233 mm². The Ryzen 9 5900 is Zen 3 (Vermeer) on a 7 nm process with a die size of 2x 74 mm² and 8,300 million transistors. The HX PRO 375 is a monolithic mobile design, while the 5900 is a dual-chiplet desktop design.

Cache configurations differ significantly. The HX PRO 375 has 80 KB of L1 per core, 1 MB of L2 per core, and 16 MB of L3. The 5900 has 64 KB of L1 per core, 512 KB of L2 per core, and a much larger 64 MB of L3. That 4x difference in L3 explains why the 5900 excels in data-heavy workloads like encryption and integer math, even with older cores.

The HX PRO 375's Zen 5 architecture brings a 4 nm process and higher boost clocks (5.10 vs 4.70 GHz), which drives its wins in single-thread PassMark and floating-point tests. The 5900's older Zen 3 cores compensate with a higher base clock (3.00 vs 2.00 GHz) and massive L3 cache. The release dates are also far apart: the 5900 launched in January 2021, while the HX PRO 375 arrived in January 2025.

The Verdict

The data makes a practical split clear. Pick the AMD Ryzen 9 5900 if your priorities are sustained multi-core rendering, data encryption, or integer-heavy compute. It wins every Cinebench test and has a 43.2% lead in prime number finding, plus an 18.8% lead in encryption. The 64 MB of L3 cache and 65W TDP make it a stronger choice for desktop workloads where power draw is not a constraint.

Pick the AMD Ryzen AI 9 HX PRO 375 if you need a mobile processor with newer architecture features. It wins PassMark single-thread by 11.6%, extended instructions by 7.8%, and floating-point math by 7.5%. The integrated Radeon 890M graphics, 28W TDP, and DDR5/LPDDR5X support make it the only viable option for a laptop build. The 4 nm process node and Zen 5 cores give it a significant efficiency and instruction-set advantage.

For a desktop builder with a AM4 motherboard, the 5900 is the obvious choice. For anyone needing a modern mobile platform, the HX PRO 375 is the only one of the two that fits. The overall average scores are nearly identical, but the workload-specific wins are decisive: old desktop muscle versus new mobile efficiency.