AMD Ryzen 9 9955HX vs AMD Ryzen AI 5 PRO 435G Comparison

The Verdict

The benchmark database places the AMD Ryzen 9 9955HX and the AMD Ryzen AI 5 PRO 435G in different performance tiers. The Ryzen 9 9955HX wins all 11 head-to-head benchmark comparisons, with the largest margins in compute-heavy workloads and the smallest in single-threaded tasks. The Ryzen 9 9955HX posts an average benchmark score of 91199, placing it in the 96th percentile of all CPUs, while the Ryzen AI 5 PRO 435G averages 40718, which lands in the 87th percentile. The data shows that the Ryzen 9 9955HX is the choice for workloads that scale with core count and parallel execution, while the Ryzen AI 5 PRO 435G serves as a more compact 6-core part for systems where the 16-core configuration is unnecessary. The Ryzen AI 5 PRO 435G, with its desktop socket and lower core count, is positioned for users who need a capable Zen 5 processor without the parallel throughput of the flagship mobile part.

Architecture Differences

The two processors share the same 4 nm TSMC process node and both use the Zen 5 architecture, but they diverge in nearly every other structural detail. The Ryzen 9 9955HX belongs to the 9000 series under the Fire Range codename, while the Ryzen AI 5 PRO 435G comes from the Ryzen AI PRO 400 generation under the Gorgon Point codename, which combines Zen 5 and Zen 5c cores.

The Ryzen 9 9955HX carries 16 cores and 32 threads, with a base clock of 2.50 GHz and a boost clock of 5.40 GHz. The Ryzen AI 5 PRO 435G has 6 cores and 12 threads, with a base clock of 2.00 GHz and a boost clock of 4.50 GHz. The Ryzen 9 9955HX has an unlocked multiplier, whereas the Ryzen AI 5 PRO 435G does not, so the former allows user-controlled overclocking while the latter is locked.

Cache configurations differ substantially. Both processors use 80 KB of L1 cache per core and 1 MB of L2 cache per core, but the Ryzen 9 9955HX has 64 MB of shared L3 cache compared to just 4 MB on the Ryzen AI 5 PRO 435G. That 16x difference in L3 capacity is a major factor in the performance gap observed in the benchmark results.

The Ryzen 9 9955HX uses AMD Socket FL1 and is classified as a mobile part, while the Ryzen AI 5 PRO 435G uses AMD Socket AM5 and is classified as a desktop part. The TDP figures are close, 55 W for the Ryzen 9 9955HX and 65 W for the Ryzen AI 5 PRO 435G, but the power envelopes do not reflect the large core count difference. Both support dual-channel DDR5 memory with an identical 89.6 GB/s memory bandwidth, and both support ECC memory.

PCIe connectivity differs. The Ryzen 9 9955HX provides Gen 5 with 28 lanes from the CPU, while the Ryzen AI 5 PRO 435G provides Gen 4 with 10 lanes from the CPU. The integrated graphics also differ: the Ryzen 9 9955HX uses the Radeon 610M, while the Ryzen AI 5 PRO 435G uses the Radeon 840M. The Ryzen 9 9955HX was released on 2025-01-05 and the Ryzen AI 5 PRO 435G on 2026-03-01, meaning the latter is a newer product but occupies a lower performance tier.

Where Each One Wins

The Ryzen 9 9955HX is the clear winner across every recorded benchmark, but the margin varies by workload type. The largest advantage appears in parallel integer and floating-point workloads. In PassMark integer math, the Ryzen 9 9955HX scores 212598 against 63707, a 233.7% lead. In floating-point math, it scores 136682 against 43494, a 214.3% lead. The 16-core, 32-thread configuration, combined with the 64 MB L3 cache, drives these results.

The Ryzen 9 9955HX also dominates in encryption and compression tasks. Data encryption shows a 208.2% advantage (37330 vs 12111), and data compression shows a 188.8% advantage (731998 vs 253484). Extended instruction workloads, which often benefit from wider execution resources, show a 209.9% lead (57946 vs 18697). Prime number finding, a heavily integer-bound test, shows the largest relative gap at 421.8% (287 vs 55).

The smallest difference appears in single-threaded performance. The PassMark single-thread score for the Ryzen 9 9955HX is 4393 versus 3829 for the Ryzen AI 5 PRO 435G, a 14.7% lead. This indicates that while the Ryzen 9 9955HX has a higher boost clock (5.40 GHz vs 4.50 GHz) and a larger cache, the per-core architecture is similar enough that the single-thread gap is modest compared to the multi-thread gap.

The Ryzen AI 5 PRO 435G does not win any of the 11 head-to-head benchmarks. Its role is defined by what it is not: a 6-core desktop processor with a locked multiplier, 4 MB of L3 cache, and Gen 4 PCIe. It does not offer the same parallel throughput, cache capacity, or I/O bandwidth as the Ryzen 9 9955HX. In workloads that do not scale with core count, such as the single-thread test, the Ryzen AI 5 PRO 435G comes closer but still trails.

FAQ

Q: Which processor has more cores?

A: The AMD Ryzen 9 9955HX has 16 cores and 32 threads, while the AMD Ryzen AI 5 PRO 435G has 6 cores and 12 threads.

Q: How large is the L3 cache difference?

A: The Ryzen 9 9955HX has 64 MB of shared L3 cache, while the Ryzen AI 5 PRO 435G has 4 MB, a 16x difference.

Q: Which processor has the higher boost clock?

A: The Ryzen 9 9955HX boosts to 5.40 GHz, while the Ryzen AI 5 PRO 435G boosts to 4.50 GHz.

Q: Do both processors support ECC memory?

A: Yes, both the Ryzen 9 9955HX and the Ryzen AI 5 PRO 435G support ECC memory, and both use dual-channel DDR5 with 89.6 GB/s bandwidth.

Q: Which processor has a larger single-thread advantage?

A: The Ryzen 9 9955HX leads in the PassMark single-thread test by 14.7%, scoring 4393 versus 3829 for the Ryzen AI 5 PRO 435G.

Q: What is the difference in PCIe support?

A: The Ryzen 9 9955HX provides PCIe Gen 5 with 28 CPU lanes, while the Ryzen AI 5 PRO 435G provides PCIe Gen 4 with 10 CPU lanes.

Head-to-Head Benchmarks

The benchmark data records 11 head-to-head comparisons, and the Ryzen 9 9955HX wins every one of them. The average benchmark score of 91199 versus 40718 reflects the overall separation, placing the Ryzen 9 9955HX in the 96th percentile and the Ryzen AI 5 PRO 435G in the 87th percentile of all CPUs.

The largest win for the Ryzen 9 9955HX is in PassMark find prime numbers, where it scores 287 against 55, a 421.8% advantage. This test is heavily dependent on integer execution and cache behavior, and the 64 MB L3 cache plus 16 cores give the Ryzen 9 9955HX an overwhelming edge. The next largest is integer math at 233.7% (212598 vs 63707), followed by floating-point math at 214.3% (136682 vs 43494).

Encryption and extended instruction workloads show similar patterns. Data encryption scores 37330 versus 12111, a 208.2% lead, and extended instructions score 57946 versus 18697, a 209.9% lead. These tests respond strongly to the wider core count and higher sustained throughput of the Ryzen 9 9955HX.

Compression and sorting workloads also favor the Ryzen 9 9955HX by large margins. Data compression shows a 188.8% lead (731998 vs 253484), and random string sorting shows a 184.2% lead (77890 vs 27407). Multithread performance, as measured by PassMark, shows a 176.9% lead (56171 vs 20285), and physics simulation shows a 172.3% lead (2720 vs 999). These results confirm that the Ryzen 9 9955HX maintains a roughly 2.7x to 3.2x advantage across most parallel workloads.

The single-thread test is the outlier. The Ryzen 9 9955HX scores 4393 versus 3829, a 14.7% lead. The two processors share the same Zen 5 architecture and 4 nm process node, and the single-thread gap is driven primarily by the higher boost clock and larger cache of the Ryzen 9 9955HX. Even in this closest comparison, the Ryzen AI 5 PRO 435G does not take a single win.

The nearest rival data places the Ryzen 9 9955HX among high-end workstation and desktop processors. It sits 0.5% above the Intel Xeon 654 (90717) and 0.7% above the AMD Ryzen AI Max+ 392 (90541), while trailing the Intel Core Ultra 7 270K Plus and Intel Xeon 6520P by 2.8% each. The Ryzen AI 5 PRO 435G, by contrast, sits within 0.5% of the Intel Xeon 6357P, Intel Core 5 223PE, Intel Core 7 253PE, and Intel Core Ultra X7 368H, all of which cluster around 40518 to 40630. This places the Ryzen AI 5 PRO 435G in a mid-range tier, far below the Ryzen 9 9955HX in absolute performance but with a competitive position against its direct peers.