AMD EPYC 9555P vs AMD EPYC 9634 Comparison

The AMD EPYC 9634 and AMD EPYC 9555P represent two distinct generations of AMD’s server platform, with the 9634 arriving as a 2022 Genoa part and the 9555P as a 2024 Turin part. While both are 99th-percentile performers, the data reveals a clear generational shift: the newer 9555P wins 15 of 17 head-to-head benchmarks, often by double-digit margins, despite having 20 fewer cores and 40 fewer threads. The 9634 holds only two wins, both in niche workloads. This analysis dissects the benchmark data, architectural divergences, and specification differences to determine where each processor excels.

Head-to-Head Benchmarks

The most striking pattern in the data is the uniformity of the 9555P’s victories. In every Cinebench test—R15, R20, and R23—the 9555P wins by exactly 20.3%, regardless of single-core or multi-core workload. The R23 multi-core score tells the story: the 9555P posts 115,186 against the 9634’s 91,752, a gap that holds steady across all rendering tests. This consistency suggests the 9555P’s architectural advantage is not workload-dependent but fundamental to its core design.

Single-threaded performance amplifies this narrative. In Cinebench R23 single-core, the 9555P scores 16,261 versus 12,953 for the 9634, a 20.3% lead. PassMark single-thread shows a similar but slightly smaller advantage: 3,410 versus 2,924, a 14.3% delta. The 9555P’s higher boost clock of 4.40 GHz against 3.70 GHz partially explains this, but the per-core IPC gains from Zen 5 over Zen 4 appear to be the dominant factor.

The 9555P’s largest wins come in compute-heavy PassMark workloads. Floating-point math shows a 27.3% advantage (486,407 vs. 353,784), and extended instructions show a 28% lead (191,082 vs. 137,543). These are the biggest percentage deltas in the entire dataset, indicating that the 9555P’s newer architecture handles complex mathematical operations and SIMD-style workloads far more efficiently. Integer math is closer at 7.8% (787,106 vs. 725,356), suggesting the 9634’s higher core count partially compensates for older architecture in this workload.

The 9634’s two wins are instructive. Data encryption goes to the 9634 by a slim 2% margin (151,943 vs. 148,896), a narrow victory that likely reflects the 84-core advantage in a workload that scales well with core count. Find prime numbers is a more decisive win: the 9634 scores 1,176 against 1,067, a 10.2% advantage. This is a highly parallel, integer-heavy workload where raw core count matters more than per-core efficiency.

Other workloads show the 9555P winning by moderate margins. Data compression sees a 15.3% lead (2,639,400 vs. 2,236,412), while multithreaded performance shows a 12.6% gap (123,576 vs. 107,944). Physics scores favor the 9555P by 20.6% (15,474 vs. 12,291), and random string sorting shows the smallest 9555P win at 6.9% (280,398 vs. 261,134). The overall average benchmark score tells the same story: the 9555P averages 287,066 against the 9634’s 244,274, a difference of roughly 17.5%.

FAQ

Q: Why does the EPYC 9555P win most benchmarks despite having fewer cores?

A: The 9555P uses the newer Zen 5 architecture on a 4 nm process node, compared to the 9634’s Zen 4 on 5 nm. This architectural leap delivers higher per-core performance—evidenced by a 20.3% lead in Cinebench R23 single-core (16,261 vs. 12,953)—which more than offsets its 64-core count against the 9634’s 84 cores.

Q: In which specific workloads does the EPYC 9634 outperform the 9555P?

A: The 9634 wins in exactly two areas: data encryption (151,943 vs. 148,896, a 2% edge) and find prime numbers (1,176 vs. 1,067, a 10.2% edge). Both are highly parallel, integer-heavy workloads where the 9634’s 20 additional cores provide a tangible advantage.

Q: How significant is the 9555P’s lead in floating-point and extended instruction workloads?

A: These are the 9555P’s largest wins. Floating-point math shows a 27.3% advantage (486,407 vs. 353,784), and extended instructions show a 28% lead (191,082 vs. 137,543). These deltas indicate that the Zen 5 architecture is substantially more efficient at mathematical and SIMD operations.

Q: Does the 9634’s larger L3 cache help it in any measurable way?

A: The 9634 has 384 MB of shared L3 cache versus the 9555P’s 256 MB. Despite this 50% cache capacity advantage, the 9555P still wins most cache-sensitive workloads like data compression by 15.3%. The newer architecture appears to use its smaller cache more efficiently.

Q: How do these processors compare to their nearest rivals?

A: The 9634 sits 2.5% ahead of the Intel Xeon 6747P (238,263 avg score) and 2.9% behind the Intel Xeon 6980P (251,516). The 9555P is nearly tied with the Intel Xeon 696X (0.3% ahead) and the AMD EPYC 9565 (0.6% ahead), while leading the Intel Xeon 6780E by 2.4%.

Q: What does the 20.3% uniform delta in Cinebench tests indicate?

A: The exact same 20.3% margin across all six Cinebench tests (R15, R20, R23, both single and multi-core) suggests a consistent architectural efficiency advantage for the 9555P. This uniformity implies the gap is not tied to thread scaling or cache behavior but to fundamental per-core performance differences.

Architecture Differences

The two processors belong to different generations and architectures. The 9634 is part of the EPYC 9004 series, built on Zen 4 architecture with the codename Genoa. The 9555P belongs to the EPYC 9005 series, using Zen 5 architecture with the codename Turin. This generational gap is the primary driver of the benchmark differences.

Process technology differs significantly. The 9634 uses a 5 nm process from TSMC, while the 9555P uses a smaller 4 nm process from the same foundry. The transistor count reflects this: the 9634 packs 78,840 million transistors across 12 dies of 72 mm² each, while the 9555P has 66,520 million transistors across 8 dies of 70.6 mm² each. The 9555P achieves higher performance with fewer transistors and dies, demonstrating the efficiency gains of the newer node.

Cache architecture shows notable differences beyond total capacity. The 9634 has 64 KB of L1 cache per core, while the 9555P has 80 KB per core. Both share 1 MB of L2 per core. The L3 cache differs: the 9634 offers 384 MB shared, while the 9555P provides 256 MB shared. The 9555P's larger per-core L1 cache likely contributes to its single-thread performance advantage.

Clock speeds favor the 9555P. The 9555P has a base clock of 3.20 GHz and a boost clock of 4.40 GHz, compared to the 9634's 2.25 GHz base and 3.70 GHz boost. This 0.70 GHz boost clock advantage is substantial and helps explain the 9555P's single-thread wins.

Memory support is similar but not identical. Both support DDR5 with twelve-channel memory buses. However, the 9555P has higher memory bandwidth at 576.0 GB/s versus the 9634's 460.8 GB/s. Both support ECC memory and offer PCIe Gen 5 with 128 lanes.

The 9634 has a TDP of 290 W, while the 9555P has a higher TDP of 360 W. This 70 W difference reflects the 9555P's higher clocks and newer architecture requiring more power.

The Verdict

The data presents a clear picture: the AMD EPYC 9555P is the superior processor in nearly every measurable workload. Its 15 wins out of 17 head-to-head benchmarks, including all Cinebench tests and the majority of PassMark workloads, demonstrate that the Zen 5 architecture on 4 nm provides a decisive performance advantage over the Zen 4-based 9634. The 9555P's 17.5% higher average benchmark score (287,066 vs. 244,274) is substantial, especially considering it achieves this with 20 fewer cores.

The 9634's advantages are narrow and specialized. Its wins in data encryption (2%) and find prime numbers (10.2%) suggest that workloads which scale almost perfectly with core count and resist architectural improvements can still favor the 84-core part. For organizations running such workloads, the 9634 remains relevant.

However, the 9555P's uniform 20.3% lead across all Cinebench tests, combined with 27-28% advantages in floating-point and extended instructions, indicates that the newer architecture is not just faster per core but fundamentally more efficient. The 9555P also offers higher memory bandwidth (576.0 GB/s vs. 460.8 GB/s), which benefits memory-bound applications.

The 9634 does have a larger L3 cache (384 MB vs. 256 MB), which could benefit certain database or analytics workloads. Yet the benchmark data shows the 9555P winning data compression by 15.3%, suggesting the architecture's efficiency outweighs cache capacity in practice.

Specification Differences

| Specification | AMD EPYC 9634 | AMD EPYC 9555P |

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

| Series | EPYC 9004 series | EPYC 9005 series |

| Architecture | Zen 4 | Zen 5 |

| Codename | Genoa | Turin |

| Process Node | 5 nm | 4 nm |

| Transistors | 78,840 million | 66,520 million |

| Die Size | 12x 72 mm² | 8x 70.6 mm² |

| Cores | 84 | 64 |

| Threads | 168 | 128 |

| Base Clock | 2.25 GHz | 3.20 GHz |

| Boost Clock | 3.70 GHz | 4.40 GHz |

| L1 Cache | 64 KB (per core) | 80 KB (per core) |

| L2 Cache | 1 MB (per core) | 1 MB (per core) |

| L3 Cache | 384 MB (shared) | 256 MB (shared) |

| Memory Bandwidth | 460.8 GB/s | 576.0 GB/s |

| TDP | 290 W | 360 W |

| Release Date | 2022-11-09 | 2024-10-09 |

| Launch MSRP | $10304 | $7983 |

Where Each One Wins

AMD EPYC 9555P wins in: All Cinebench rendering workloads (R15, R20, R23) by a consistent 20.3% margin, both single-core and multi-core. PassMark floating-point math (27.3% ahead), extended instructions (28% ahead), integer math (7.8% ahead), multithreaded performance (12.6% ahead), physics (20.6% ahead), data compression (15.3% ahead), random string sorting (6.9% ahead), and single-threaded performance (14.3% ahead). The 9555P is the clear choice for general-purpose compute, scientific simulation, rendering, encryption-adjacent workloads, and any application that benefits from high single-thread performance. Its higher memory bandwidth also makes it preferable for memory-intensive workloads.

AMD EPYC 9634 wins in: Data encryption (2% ahead) and find prime numbers (10.2% ahead). The 9634 is the better option for workloads that scale almost perfectly with core count and are resistant to architectural improvements. Prime number finding and certain encryption algorithms fall into this category. The 9634's 84 cores and 168 threads give it a raw parallel throughput advantage that the 9555P's architecture cannot overcome in these specific scenarios. For organizations running such niche workloads at scale, the 9634's 20 additional cores provide a measurable, if narrow, benefit. The 9634 also has 128 MB more L3 cache, which could prove advantageous in specific cache-resident workloads not captured in the benchmark suite.