AMD EPYC 8534P vs AMD EPYC 9455P Comparison

The AMD EPYC 9455P and AMD EPYC 8534P are two server processors aimed at different deployment scenarios, and the benchmark data shows a clear performance hierarchy between them. The 9455P, built on the newer Zen 5 architecture, dominates nearly every workload in the comparison, while the 8534P offers a specific niche advantage in one area. This analysis breaks down their head-to-head results, architectural differences, and ideal use cases based strictly on the provided data.

Head-to-Head Benchmarks

The EPYC 9455P is the overwhelming winner in this comparison, taking 16 of the 17 benchmark tests. The most dramatic gaps appear in multi-threaded and physics-based workloads. In Cinebench R15 multicore, the 9455P scores 9999 against the 8534P’s 6160, a 62.3% advantage. That margin repeats almost exactly across Cinebench R20 (41666 vs 25668) and R23 (99206 vs 61115), both showing 62.3% deltas. Single-core Cinebench results tell the same story: the 9455P leads by 62.4% in R15 (1411 vs 869) and R20 (5882 vs 3623), and by 62.3% in R23 (14005 vs 8628).

PassMark’s multithread test shows a 62.6% win for the 9455P (116927 vs 71900), aligning with the Cinebench multicore pattern. The single-thread PassMark result is slightly closer but still decisive: 3745 vs 2441, a 53.4% lead. The most extreme outlier is PassMark physics, where the 9455P scores 17315 versus 3667 — a 372.2% difference that suggests a massive per-clock or per-core efficiency advantage in that specific simulation workload.

Other PassMark subtests show narrower but still substantial wins. Integer math favors the 9455P by 17.8% (606239 vs 514526), floating-point math by 23.6% (357783 vs 289443), and extended instructions by 21.8% (137485 vs 112860). Random string sorting is a 87.4% win for the 9455P (242701 vs 129479), while data compression is closer at 7.7% (1928897 vs 1791742). Prime number finding is another lopsided result: 1107 vs 278, a 298.2% advantage for the 9455P.

The single benchmark where the 8534P wins is PassMark data encryption, scoring 121728 against 115403 — a 5.2% edge. This is notable because it breaks the otherwise consistent pattern of 9455P dominance, suggesting the 8534P’s different core design or memory configuration has a specific strength in encryption throughput.

Architecture Differences

The two processors come from different EPYC families and use different silicon. The 9455P is part of the EPYC 9005 series, built on Zen 5 architecture with the codename Turin. It uses a 4 nm process node from TSMC and integrates 66,520 million transistors across a die size of 8x 70.6 mm². The 8534P belongs to the EPYC 8004 series, using Zen 4c architecture with the codename Siena. It is fabbed on a 5 nm node and contains 35,500 million transistors over a die size of 4x 73 mm².

Core counts differ in an interesting way: the 8534P has more cores (64 vs 48) and more threads (128 vs 96), yet it loses in nearly every benchmark. This points to a significant per-core performance gap between Zen 5 and Zen 4c. The 9455P’s base clock is 3.15 GHz with a boost of 4.40 GHz, while the 8534P runs at 2.30 GHz base and 3.10 GHz boost — a 1.3 GHz difference at boost that explains much of the single-thread gap.

Cache hierarchies also differ substantially. The 9455P offers 80 KB L1 per core, 1 MB L2 per core, and 256 MB shared L3. The 8534P has 64 KB L1 per core, 1 MB L2 per core, and 128 MB shared L3. The 9455P thus provides double the L3 capacity and more per-core L1.

Memory support is another major divergence. Both support DDR5 with ECC, but the 9455P uses a twelve-channel memory bus with 576.0 GB/s bandwidth, while the 8534P is limited to six channels and 230.4 GB/s. That is a 2.5x raw memory bandwidth advantage for the 9455P, which likely contributes to its leads in data-heavy workloads like compression and random string sorting. PCIe connectivity also favors the 9455P: 128 Gen 5 lanes versus 96 Gen 5 lanes for the 8534P.

Socket and platform differences are significant for system planning. The 9455P uses AMD Socket SP5, while the 8534P uses AMD Socket SP6. These are not interchangeable, meaning a motherboard choice locks in one processor family. Power envelopes differ as well: the 9455P has a 300 W TDP, while the 8534P is rated at 200 W — a 100 W gap that reflects the higher performance and bandwidth of the 9455P.

FAQ

Q: Which processor has more cores?

A: The AMD EPYC 8534P has 64 cores and 128 threads, compared to 48 cores and 96 threads on the EPYC 9455P.

Q: Why does the 9455P win in most benchmarks despite having fewer cores?

A: The 9455P uses Zen 5 architecture on a 4 nm node with higher clock speeds (4.40 GHz boost vs 3.10 GHz), double the L3 cache (256 MB vs 128 MB), and a twelve-channel memory bus (576.0 GB/s vs 230.4 GB/s). These factors outweigh the 8534P’s core count advantage.

Q: Is there any workload where the 8534P is faster?

A: Yes, in PassMark data encryption, the 8534P scores 121728 versus 115403, a 5.2% advantage. This is the only test among 17 where the 8534P wins.

Q: Do these processors use the same motherboard socket?

A: No. The 9455P uses AMD Socket SP5, while the 8534P uses AMD Socket SP6. They are incompatible with each other.

Q: What is the memory bandwidth difference?

A: The 9455P supports twelve-channel DDR5 with 576.0 GB/s bandwidth. The 8534P supports six-channel DDR5 with 230.4 GB/s bandwidth — a 2.5x difference favoring the 9455P.

Q: Which processor has a higher TDP?

A: The 9455P has a 300 W TDP, while the 8534P has a 200 W TDP. The 9455P consumes more power but delivers significantly higher performance in most tests.

The Verdict

The data points to a clear recommendation for most buyers: the AMD EPYC 9455P is the superior processor for general compute, multi-threaded rendering, and single-thread performance. Its wins are consistent and often massive — 62.3% in Cinebench multicore, 62.4% in single-core, and 372.2% in PassMark physics. The 9455P also holds a 99th percentile ranking among all CPUs, versus 98th for the 8534P. Its average benchmark score is 217854, compared to 185092 for the 8534P, a 17.7% overall gap.

The 8534P should only be chosen if the specific encryption workload is a priority, or if the lower 200 W TDP and smaller physical footprint (4x 73 mm² dies vs 8x 70.6 mm²) matter for a power-constrained deployment. However, the 8534P’s 64 cores do not translate into wins in any multi-core test, and its six-channel memory bus is a severe limiting factor for bandwidth-sensitive applications.

Given that the 9455P launched at $4819 and the 8534P at $4950, the price difference is negligible relative to the performance gap. The 9455P offers dramatically better performance for nearly the same launch MSRP, making it the rational choice for any workload that does not specifically require the 8534P’s encryption edge or lower power draw.

Specification Differences

| Specification | AMD EPYC 9455P | AMD EPYC 8534P |

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

| Series | EPYC 9005 series | EPYC 8004 series |

| Architecture | Zen 5 | Zen 4c |

| Codename | Turin | Siena |

| Process Node | 4 nm | 5 nm |

| Transistors | 66,520 million | 35,500 million |

| Die Size | 8x 70.6 mm² | 4x 73 mm² |

| Cores | 48 | 64 |

| Threads | 96 | 128 |

| Base Clock | 3.15 GHz | 2.30 GHz |

| Boost Clock | 4.40 GHz | 3.10 GHz |

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

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

| L3 Cache | 256 MB (shared) | 128 MB (shared) |

| Memory Bus | Twelve-channel | Six-channel |

| Memory Bandwidth | 576.0 GB/s | 230.4 GB/s |

| PCIe Lanes | Gen 5, 128 Lanes | Gen 5, 96 Lanes |

| Socket | AMD Socket SP5 | AMD Socket SP6 |

| TDP | 300 W | 200 W |

| Launch MSRP | $4819 | $4950 |

| Release Date | 2024-10-09 | 2023-09-17 |

Where Each One Wins

The EPYC 9455P wins in every measured category except one. For multi-threaded workloads like Cinebench R15/R20/R23 and PassMark multithread, the 9455P is consistently about 62% faster. For single-threaded tasks, it leads by 53-62% depending on the test. In math-heavy operations such as integer math (17.8% lead), floating-point math (23.6%), and prime number finding (298.2%), the 9455P is clearly superior. Physics simulation is its biggest win at 372.2% over the 8534P. Data compression and sorting tasks also favor the 9455P, with 7.7% and 87.4% leads respectively.

The 8534P has exactly one winning scenario: data encryption, where it beats the 9455P by 5.2%. This suggests that for workloads heavily dependent on encryption/decryption throughput, the 8534P’s core configuration or memory subsystem has an advantage. Additionally, its 200 W TDP versus 300 W means it is the lower-power option, which could be relevant for dense server deployments where thermal and power budgets are tight. However, that lower power does not translate into better performance in any other benchmark.

For practical use cases, the 9455P is the pick for general-purpose compute, virtualization, database workloads, rendering, and any task that benefits from high memory bandwidth or high single-thread performance. The 8534P is best reserved for encryption-heavy services or scenarios where the 200 W power envelope is a hard constraint and the 64-core count is necessary for core-count licensing or allocation, despite its lower per-core performance.