AMD Ryzen 9 9955HX3D vs AMD Ryzen AI 7 345 Comparison

Head-to-Head Benchmarks

The benchmark data shows a dominant performance profile for the AMD Ryzen 9 9955HX3D across every recorded test. The Ryzen 9 9955HX3D wins all 15 head-to-head comparisons, with the largest margins appearing in compute-heavy workloads. The most extreme delta is in the PassMark find prime numbers test, where the Ryzen 9 9955HX3D scores 525 against the Ryzen AI 7 345's 62, a 746.8% advantage. This test is highly sensitive to raw integer throughput and cache hierarchy, so the scale of the gap reflects the architectural gulf between the two parts.

In Cinebench R15 multicore, the Ryzen 9 9955HX3D records 6042.5 points versus 1712 for the Ryzen AI 7 345, a 252.9% lead. Cinebench R23 multicore shows a similar pattern: 38161.5 against 11461, a 233% difference. These are the two most widely referenced multi-threaded rendering workloads in the database, and the results indicate that the Ryzen 9 9955HX3D delivers roughly three and a half times the multi-core performance of the Ryzen AI 7 345 in these tests.

Single-threaded performance is much closer but still favors the Ryzen 9 9955HX3D. In Cinebench R15 single-core, the scores are 332 versus 271, a 22.5% lead. Cinebench R23 single-core shows 2159.5 against 1818, an 18.8% advantage. PassMark single-thread records 4511 versus 3875, a 16.4% gap. The single-thread deltas are consistent across all three tests, suggesting a modest clock-speed and per-core efficiency advantage for the Ryzen 9 9955HX3D rather than a workload-specific effect.

The PassMark suite provides additional granularity. In integer math, the Ryzen 9 9955HX3D scores 222503 versus 63475, a 250.5% lead. Floating-point math shows 144122 against 42621, a 238.1% difference. Extended instructions (SIMD workloads) show 62813 versus 17003, a 269.4% gap. Data compression and encryption follow the same pattern: 785811 versus 237484 (230.9%) and 39446 versus 11814 (233.9%), respectively. Random string sorting shows 83497 against 25435, a 228.3% lead. PassMark multithread records 62674 versus 19927, a 214.5% difference, while the physics test shows 4687 against 1089, a 330.4% gap.

These numbers confirm that the Ryzen 9 9955HX3D does not merely outperform the Ryzen AI 7 345; it outperforms it by margins that suggest entirely different performance tiers. The smallest delta in the entire head-to-head set is 16.4% in single-threaded PassMark, which is still a decisive win. The average benchmark score for the Ryzen 9 9955HX3D is 97453, placing it in the 96th percentile of all CPUs in the database. The Ryzen AI 7 345 has an average score of 29461, placing it in the 81st percentile. The Ryzen 9 9955HX3D sits close to the AMD Ryzen Threadripper PRO 5965WX (98504, a 1.1% delta) and ahead of the AMD Ryzen 9 PRO 9945 (96083, a 1.4% delta) in average score. The Ryzen AI 7 345 sits near the AMD Ryzen 7 3800X (29447, a 0% delta) and the Intel Core i5-13500HX (29270, a 0.7% delta).

Architecture Differences

The two processors come from different families within AMD's mobile lineup. The Ryzen 9 9955HX3D belongs to the 9000 series, uses the Zen 5 architecture, and carries the Fire Range codename. The Ryzen AI 7 345 belongs to the Ryzen AI 300 series and uses a hybrid Zen 5 / Zen 5c configuration under the Krackan Point codename. Both are built on a 4 nm process at TSMC, but the similarity ends there.

Core and thread counts differ substantially. The Ryzen 9 9955HX3D has 16 cores and 32 threads, while the Ryzen AI 7 345 has 6 cores and 12 threads. This 10-core and 20-thread difference is the primary driver of the multi-threaded benchmark gaps. Clock speeds also favor the larger chip: the Ryzen 9 9955HX3D has a base clock of 2.50 GHz and a boost clock of 5.40 GHz, while the Ryzen AI 7 345 has a 2.00 GHz base and a 4.60 GHz boost. The higher boost clock contributes to the single-threaded wins.

Cache configuration is a major differentiator. The Ryzen 9 9955HX3D has 80 KB of L1 per core, 1 MB of L2 per core, and a 128 MB L3 cache. The Ryzen AI 7 345 also has 80 KB of L1 per core and 1 MB of L2 per core, but only 4 MB of L3. The 124 MB L3 gap strongly influences the find prime numbers result and other cache-sensitive workloads. The Ryzen 9 9955HX3D also has a larger transistor count (16,630 million) and a die size of 2x 70.6 mm², while the Ryzen AI 7 345 has no recorded transistor count or die size in the database.

Memory and I/O differ as well. Both support DDR5 with dual-channel memory and 89.6 GB/s bandwidth. The Ryzen AI 7 345 also supports LPDDR5X, giving it flexibility for lower-power designs. The Ryzen 9 9955HX3D supports ECC memory, while the Ryzen AI 7 345 does not. PCIe connectivity favors the Ryzen 9 9955HX3D with Gen 5 and 28 lanes (CPU only), versus Gen 4 and 14 lanes (CPU only) for the Ryzen AI 7 345. The integrated graphics differ too: the Ryzen 9 9955HX3D uses the Radeon 610M, while the Ryzen AI 7 345 uses the Radeon 840M.

Power targets are far apart. The Ryzen 9 9955HX3D has a TDP of 55, while the Ryzen AI 7 345 has a TDP of 28. The Ryzen 9 9955HX3D uses AMD Socket FL1, while the Ryzen AI 7 345 uses AMD Socket FP8. The multiplier is unlocked on the Ryzen 9 9955HX3D but locked on the Ryzen AI 7 345. Release dates are close: January 5, 2025 for the Ryzen 9 9955HX3D and January 14, 2025 for the Ryzen AI 7 345. Part numbers are 100-000001030 and 100-000002122, respectively.

FAQ

Q: How much faster is the Ryzen 9 9955HX3D in multi-threaded rendering?

A: In Cinebench R23 multicore, the Ryzen 9 9955HX3D scores 38161.5 against 11461 for the Ryzen AI 7 345, a 233% advantage. In Cinebench R15 multicore, the gap is 252.9% (6042.5 versus 1712).

Q: Is the single-threaded performance gap large?

A: No, it is much smaller than the multi-threaded gap. The Ryzen 9 9955HX3D leads by 22.5% in Cinebench R15 single-core (332 versus 271), 18.8% in Cinebench R23 single-core (2159.5 versus 1818), and 16.4% in PassMark single-thread (4511 versus 3875).

Q: What explains the huge difference in the prime numbers test?

A: The Ryzen 9 9955HX3D has a 128 MB L3 cache versus 4 MB on the Ryzen AI 7 345, combined with 16 cores versus 6. The find prime numbers workload is cache and integer-throughput sensitive, and the Ryzen 9 9955HX3D scores 525 versus 62, a 746.8% lead.

Q: Which processor supports ECC memory?

A: The Ryzen 9 9955HX3D supports ECC memory. The Ryzen AI 7 345 does not.

Q: Do both processors use the same memory type?

A: Both support DDR5 with dual-channel memory and 89.6 GB/s bandwidth. The Ryzen AI 7 345 adds LPDDR5X support, which the Ryzen 9 9955HX3D does not list.

Q: How do their average benchmark scores compare to other CPUs?

A: The Ryzen 9 9955HX3D has an average score of 97453 (96th percentile), close to the AMD Ryzen Threadripper PRO 5965WX at 98504. The Ryzen AI 7 345 has an average score of 29461 (81st percentile), nearly matching the AMD Ryzen 7 3800X at 29447.

Specification Differences

The two processors differ in nearly every major specification category. Core count: 16 versus 6. Thread count: 32 versus 12. Base clock: 2.50 GHz versus 2.00 GHz. Boost clock: 5.40 GHz versus 4.60 GHz. TDP: 55 versus 28. Socket: AMD Socket FL1 versus AMD Socket FP8. Codename: Fire Range versus Krackan Point. Generation: Ryzen 9 (Zen 5, Fire Range) versus Ryzen AI 300 (Zen 5 / Zen 5c). Process node is the same (4 nm, TSMC), but the Ryzen 9 9955HX3D records 16,630 million transistors and a 2x 70.6 mm² die size, while the Ryzen AI 7 345 has no recorded values. L3 cache: 128 MB versus 4 MB. Memory support: DDR5 versus DDR5 and LPDDR5X. ECC memory: supported versus not supported. PCIe: Gen 5 with 28 lanes versus Gen 4 with 14 lanes. Integrated graphics: Radeon 610M versus Radeon 840M. Multiplier: unlocked versus locked. Release date: January 5, 2025 versus January 14, 2025. Part number: 100-000001030 versus 100-000002122. The Ryzen 9 9955HX3D belongs to the 9000 series, while the Ryzen AI 7 345 has no series listed.

Where Each One Wins

The Ryzen 9 9955HX3D wins every recorded benchmark, so the use-case split is defined by the margin of victory rather than by the direction. For multi-threaded rendering, video encoding, compilation, simulation, and any workload that scales with core count, the Ryzen 9 9955HX3D is in a different class. Its 16 cores and 32 threads produce Cinebench R23 multicore scores that are 233% higher, and PassMark multithread scores that are 214.5% higher. The 128 MB L3 cache makes it particularly strong for cache-resident data sets, as shown by the 746.8% lead in prime number finding and the 269.4% lead in extended instructions.

The Ryzen AI 7 345 wins in the areas of power efficiency and platform flexibility. Its 28 TDP is roughly half of the Ryzen 9 9955HX3D's 55 TDP, making it suitable for thinner, fanless or low-noise mobile designs. It supports both DDR5 and LPDDR5X, giving system designers more memory options. Its Radeon 840M integrated graphics is a newer part than the Radeon 610M in the Ryzen 9 9955HX3D, which may matter for light gaming or media acceleration in a compact chassis. For workloads that are lightly threaded, such as office productivity or web browsing, the single-thread gap narrows to the 16.4% to 22.5% range, so the Ryzen AI 7 345 remains usable despite the performance deficit.

The data indicates that these are not competing products for the same buyer. The Ryzen 9 9955HX3D is positioned at the top of the mobile performance stack, as evidenced by its 96th percentile ranking and its proximity to the AMD Ryzen Threadripper PRO 5965WX in average score. The Ryzen AI 7 345 occupies the mid-range mobile segment, with an 81st percentile ranking and an average score near the AMD Ryzen 7 3800X and the Intel Core i5-13500HX. The choice between them depends on whether the workload demands maximum multi-threaded throughput or a balance of modest performance and lower power draw.