AMD Ryzen 9 9955HX3D vs Intel Core Ultra 5 338H Comparison

Head-to-Head Benchmarks

The recorded data shows a decisive sweep for the AMD Ryzen 9 9955HX3D across every benchmark in the comparison set. The Intel Core Ultra 5 338H does not win a single recorded test, with all 15 head-to-head comparisons favoring the AMD part. The scale of the margins, however, varies dramatically between single-threaded and heavily parallel workloads.

In Cinebench R23 multi-core, the AMD Ryzen 9 9955HX3D scores 38,161.5 points against 16,331 for the Intel Core Ultra 5 338H, a 133.7% advantage. The older Cinebench R15 multi-core test shows a similar pattern: 6,042.5 versus 2,504, a 141.3% lead for AMD. These are the largest margins in the rendering benchmarks, and they reflect the core and thread count disparity between the two processors.

Single-thread performance tells a much closer story. In Cinebench R23 single-core, the AMD chip scores 2,159.5 against 2,044 for Intel, a 5.7% edge. The R15 single-core result shows an 8.9% gap, 332 versus 305. PassMark's single-thread test records 4,511 for AMD and 4,180 for Intel, a 7.9% difference. These numbers indicate that the architectural efficiency of the Intel Panther Lake design narrows the gap substantially when only one core is active, but the AMD part still holds a consistent lead.

Moving to PassMark's compute suite, the differences grow larger. Integer math shows the most extreme spread: 222,503 for AMD versus 64,934 for Intel, a 242.7% advantage. Data compression follows at 184.2%, with scores of 785,811 and 276,539 respectively. Extended instructions produce a 162.7% gap, 62,813 versus 23,906. Random string sorting records a 145% lead, while multithread performance shows 118.2% (62,674 versus 28,717).

Floating-point math, physics, and prime number tests all land in a similar range. Floating-point math scores 144,122 against 84,067, a 71.4% advantage. Physics records 4,687 versus 2,697, a 73.8% gap. Prime number finding shows 525 against 304, a 72.7% lead. Data encryption produces the smallest multi-core margin at 84.6%, with 39,446 versus 21,367.

The average benchmark score in the database places the AMD Ryzen 9 9955HX3D at 97,453, while the Intel Core Ultra 5 338H sits at 33,989. That is roughly 2.9 times the average score for the Intel part. The AMD processor ranks in the 96th percentile of all CPUs tracked, versus the 84th percentile for the Intel chip. For context, the AMD part's nearest rivals by average score are the AMD Ryzen Threadripper PRO 5965WX at 98,504 (a 1.1% gap), the AMD Ryzen 9 PRO 9945 at 96,083 (1.4% ahead of the 9955HX3D), and the AMD EPYC 4565P at 95,764 (1.8% gap). The Intel Core Ultra 5 338H sits within 0.3% of the Intel Core Ultra 7 165H and within 0.3% of the Intel Core i7-12800HX, meaning it trades places with those parts depending on the exact workload mix.

Architecture Differences

The two processors come from fundamentally different design philosophies. The AMD Ryzen 9 9955HX3D uses the Zen 5 architecture on the Fire Range codename, built on a 4 nm TSMC process. It contains 16 cores and 32 threads, with a base clock of 2.50 GHz and a boost clock of 5.40 GHz. The thermal design power is 55 watts. The chip uses the AMD Socket FL1 and has an unlocked multiplier.

The Intel Core Ultra 5 338H belongs to the Core Ultra Series 3, using the Panther Lake architecture on a 3 nm Intel process. It has 12 cores and 12 threads, with a base clock of 1.90 GHz and a boost clock of 4.70 GHz. The thermal design power is 25 watts. It uses the Intel BGA 2540 socket and has a locked multiplier.

Cache layouts differ substantially. The AMD part provides 80 KB of L1 per core and 1 MB of L2 per core, adding up to a large shared L3 pool of 128 MB. The Intel part offers 192 KB of L1 per core and 2.5 MB of L2 per core, but only 18 MB of shared L3. The 128 MB L3 on the AMD side is a defining feature, as it enables larger working sets to remain on-chip during data-heavy workloads. The Intel part's smaller L3 forces more frequent trips to memory.

Memory support also diverges. The AMD Ryzen 9 9955HX3D uses DDR5 with dual-channel memory and a recorded bandwidth of 89.6 GB/s. It supports ECC memory. The Intel Core Ultra 5 338H uses LPDDR5X with dual-channel memory and a recorded bandwidth of 136.5 GB/s. It does not support ECC. Despite the AMD part's lower memory bandwidth figure, its larger cache and higher core count compensate in many workloads.

PCIe connectivity differs sharply. The AMD chip supports Gen 5 with 28 lanes from the CPU. The Intel chip supports Gen 5 with only 4 lanes from the CPU. This makes the AMD part far more suitable for systems with multiple high-speed NVMe drives or discrete GPUs that need direct CPU lanes.

Integrated graphics also differ. The AMD Ryzen 9 9955HX3D includes a Radeon 610M. The Intel Core Ultra 5 338H includes an Arc B370. Neither is the primary focus for a database comparison, but the Intel part's integrated GPU carries a different performance profile for light graphics tasks.

Release dates place the AMD part at January 5, 2025, while the Intel part arrived on January 4, 2026. Both are listed as Active in production status and target the mobile market segment.

The Verdict

The data indicates that the AMD Ryzen 9 9955HX3D is the stronger processor in every recorded benchmark. Multi-threaded workloads show the largest gaps, with integer math at 242.7%, data compression at 184.2%, and extended instructions at 162.7%. Even single-thread tests, where the Intel part is closest, still favor AMD by margins between 5.7% and 8.9%.

The Intel Core Ultra 5 338H does have advantages in the specification sheet. It uses a 3 nm process versus 4 nm, draws 25 watts versus 55 watts, and supports LPDDR5X with higher memory bandwidth at 136.5 GB/s versus 89.6 GB/s. It also has a larger L1 and L2 per core. But none of those advantages translate into a benchmark win in the recorded data.

For workloads that depend on many cores, high L3 capacity, or extensive PCIe lanes, the AMD part is the clear choice. For workloads that prioritize lower power draw and a smaller physical footprint, the Intel part may fit a different system design, but the benchmark results show it will lag substantially in compute throughput.

The 96th percentile ranking for the AMD part versus the 84th percentile for Intel places them in different performance tiers entirely. The AMD chip competes with workstation-class processors like the Ryzen Threadripper PRO 5965WX and EPYC 4565P, while the Intel chip sits alongside mid-range mobile parts like the Core Ultra 7 165H and Core i7-12800HX.

FAQ

Q: Which CPU has more cores and threads?

A: The AMD Ryzen 9 9955HX3D has 16 cores and 32 threads. The Intel Core Ultra 5 338H has 12 cores and 12 threads.

Q: What is the largest recorded performance gap between them?

A: The largest gap is in PassMark integer math, where the AMD chip scores 222,503 versus 64,934 for Intel, a 242.7% advantage.

Q: How close are they in single-thread performance?

A: In Cinebench R23 single-core, the AMD chip leads by 5.7% (2,159.5 versus 2,044). In PassMark single-thread, the lead is 7.9% (4,511 versus 4,180).

Q: Which chip has more L3 cache?

A: The AMD Ryzen 9 9955HX3D has 128 MB of L3 cache. The Intel Core Ultra 5 338H has 18 MB of shared L3.

Q: Do both chips support ECC memory?

A: No. The AMD Ryzen 9 9955HX3D supports ECC memory. The Intel Core Ultra 5 338H does not.

Q: What are the thermal design power ratings?

A: The AMD chip has a TDP of 55 watts. The Intel chip has a TDP of 25 watts.

Where Each One Wins

The AMD Ryzen 9 9955HX3D wins every recorded benchmark, so the distinctions come down to the magnitude of the win and the workload characteristics.

For rendering and multi-threaded productivity, the AMD part dominates. Cinebench R23 multi-core shows a 133.7% lead, and Cinebench R15 multi-core shows 141.3%. These workloads benefit from the 16 cores, 32 threads, and the 128 MB L3 cache. The Intel part's 12 cores and 12 threads cannot compete when all cores are active.

For data-heavy operations, the AMD chip again leads decisively. Data compression shows a 184.2% advantage, and random string sorting shows 145%. The large L3 cache likely helps keep frequently accessed data on-chip.

For encryption and instruction-heavy code, the AMD part leads by 84.6% in data encryption and 162.7% in extended instructions. These tasks scale with core count and cache capacity, both of which favor AMD.

For floating-point and physics calculations, the AMD chip leads by 71.4% and 73.8% respectively. Prime number finding shows a 72.7% gap. These are compute-bound tasks where the higher core count and boost clock of 5.40 GHz versus 4.70 GHz provide the edge.

For single-threaded responsiveness, the AMD part still wins, but by a smaller margin. The 5.7% to 8.9% range in single-core tests indicates that the Intel Panther Lake architecture is comparatively efficient per core. The Intel chip's higher base clock per watt and 3 nm process likely contribute to this closer result.

The Intel Core Ultra 5 338H does not hold a performance win in any recorded test. Its advantages are in power efficiency (25 watts versus 55 watts), process node (3 nm versus 4 nm), and memory bandwidth (136.5 GB/s versus 89.6 GB/s). For systems where those characteristics matter more than raw compute throughput, the Intel part may be acceptable, but the database shows no workload where it outperforms the AMD chip.

Specification Differences

| Field | AMD Ryzen 9 9955HX3D | Intel Core Ultra 5 338H |

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

| Cores | 16 | 12 |

| Threads | 32 | 12 |

| Base Clock | 2.50 GHz | 1.90 GHz |

| Boost Clock | 5.40 GHz | 4.70 GHz |

| TDP | 55 W | 25 W |

| Socket | AMD Socket FL1 | Intel BGA 2540 |

| Architecture | Zen 5 | Panther Lake |

| Codename | Fire Range | Panther Lake |

| Process Node | 4 nm | 3 nm |

| Foundry | TSMC | Intel |

| L1 Cache | 80 KB per core | 192 KB per core |

| L2 Cache | 1 MB per core | 2.5 MB per core |

| L3 Cache | 128 MB | 18 MB shared |

| Memory Support | DDR5 | LPDDR5X |

| Memory Bandwidth | 89.6 GB/s | 136.5 GB/s |

| ECC Memory | Yes | No |

| PCIe | Gen 5, 28 Lanes | Gen 5, 4 Lanes |

| Integrated Graphics | Radeon 610M | Arc B370 |

| Unlocked Multiplier | Yes | No |

| Release Date | 2025-01-05 | 2026-01-04 |