AMD EPYC 9555P vs AMD EPYC 9565 Comparison

The AMD EPYC 9555P and AMD EPYC 9565 are both high-core-count server processors built on the same Zen 5 architecture for the SP5 platform, but the data shows they are not interchangeable. The 9555P, with 64 cores, wins the majority of benchmark comparisons, while the 9565, with 72 cores, pulls ahead decisively in specific computational workloads. The overall average benchmark score for the 9555P is 291,664, placing it 2.2% ahead of the 9565’s 285,471, with both processors sitting in the 99th percentile of all CPUs tested. This guide breaks down where each chip excels, using only the recorded scores to show which workloads favor which processor.

Head-to-Head Benchmarks

The most striking result is the sheer number of wins for the 9555P. Across the 17 recorded comparisons, the 9555P takes 14 of them, while the 9565 wins only 3. However, the margins tell a more interesting story than the raw count. In all six Cinebench tests—both single-core and multi-core across R15, R20, and R23—the 9555P wins by a razor-thin 0.2% margin. For instance, in Cinebench R23 multi-core, the 9555P scores 115,186 versus the 9565’s 114,937. Similarly, in Cinebench R20 single-core, the 9555P’s 6,829 barely edges out the 9565’s 6,814. These are effectively statistical ties, indicating that for rendering tasks that scale well with cores, the extra 8 cores of the 9565 do not translate into a real advantage, likely due to the 9555P’s higher base and boost clocks.

The PassMark suite reveals where the 9565 fights back. The most dramatic gap is in `passmark_find_prime_numbers`, where the 9565 scores 2,422, a massive 52.3% ahead of the 9555P’s 1,156. This is a crushing victory for the 9565 and suggests a significant architectural or scheduling advantage in this specific integer-based workload. The 9565 also wins `passmark_extended_instructions` by 14% (209,595 vs 180,317) and `passmark_floating_point_math` by 12.6% (549,422 vs 480,435). These are not small margins; they represent substantial performance deltas in workloads that stress SIMD and floating-point units.

Conversely, the 9555P’s wins are often larger on the other side. In `passmark_integer_math`, the 9555P scores 821,218, which is 14.4% higher than the 9565’s 717,948. The 9555P also shows strong gains in `passmark_data_encryption`, winning by 9.8% (155,805 vs 141,936), and `passmark_physics`, winning by 10.4% (19,907 vs 18,036). The `passmark_random_string_sorting` test favors the 9555P by 11.6% (325,662 vs 291,941). In `passmark_data_compression`, the 9555P wins by 2% (2,630,921 vs 2,579,631). The `passmark_multithread` score is nearly identical, with the 9555P ahead by just 0.2% (135,513 vs 135,221), and single-thread performance also favors the 9555P by 0.8% (3,726 vs 3,696).

The Verdict

The data points to the 9555P as the better all-round performer for general server workloads, despite having fewer cores. Its wins in integer math, encryption, physics, and sorting are substantial, and its near-parity in multi-threaded tests means the 64-core part is not giving up much, if anything, in throughput-heavy scenarios. The 9555P’s 2.2% lead in average benchmark score over the 9565 confirms this. If your primary concern is broad workload coverage—web serving, database transactions, virtualization, and general compute—the 9555P is the safer pick based on the scores.

The 9565 is not a failure; it is a specialist. Its massive 52.3% lead in prime number finding is a clear signal that it handles certain algorithmic tasks far better. The 14% lead in extended instructions and 12.6% lead in floating-point math also cannot be ignored. If your code is heavily vectorized, involves complex mathematical simulations, or relies on specific instruction set extensions, the 9565 will deliver meaningfully better results. The data shows a trade-off: the 9565 trades general integer performance for a massive boost in specific floating-point and instruction-heavy tasks. Choose the 9565 only if your workloads are proven to be in its three winning categories. Otherwise, the 9555P’s 14 wins out of 17 comparisons make it the default recommendation.

Architecture Differences

Both processors are built on the same foundational architecture: Zen 5, codenamed Turin, fabricated on TSMC’s 4 nm process node. They share the same AMD Socket SP5 platform, support DDR5 memory over a Twelve-channel bus with 576.0 GB/s of bandwidth, and offer Gen 5 PCIe with 128 Lanes (CPU only). The core design is also identical in per-core resources: each has 80 KB of L1 cache and 1 MB of L2 cache per core. The key differences lie in the scale of the silicon and the shared cache.

The 9565 packs 72 cores and 144 threads, while the 9555P has 64 cores and 128 threads. This core count difference is enabled by a larger physical package: the 9565 uses 12x 70.6 mm² dies and contains 99,780 million transistors, whereas the 9555P uses 8x 70.6 mm² dies and has 66,520 million transistors. This die configuration also affects the L3 cache. The 9565 has 384 MB of shared L3 cache, a full 128 MB more than the 9555P’s 256 MB. This massive L3 cache difference is likely a major factor in the 9565’s wins in floating-point and instruction-heavy tests, as it allows larger working sets to stay on-chip.

The clock speeds also differ, favoring the smaller part. The 9555P has a base clock of 3.20 GHz and a boost clock of 4.40 GHz, while the 9565 operates at 3.15 GHz base and 4.30 GHz boost. The 9555P’s higher clocks help explain its edge in single-threaded and lightly-threaded tests. The thermal design power (TDP) scales with core count: the 9555P is rated at 360 W, while the 9565 is rated at 400 W. Both have ECC memory support and are unlocked multipliers are not available for either. Both were released on 2024-10-09 and are currently Active in production.

FAQ

Q: Which processor is faster in Cinebench R23 multi-core?

A: The AMD EPYC 9555P scores 115,186, which is 0.2% higher than the AMD EPYC 9565’s 114,937. The margin is negligible.

Q: Is the 9565 ever significantly better than the 9555P?

A: Yes, in the PassMark `find_prime_numbers` test, the 9565 scores 2,422, which is 52.3% higher than the 9555P’s 1,156. It also wins `extended_instructions` by 14% and `floating_point_math` by 12.6%.

Q: What is the average benchmark score for each CPU?

A: The 9555P has an average benchmark score of 291,664, while the 9565 scores 285,471. The 9555P is 2.2% higher.

Q: Do both CPUs support the same memory and PCIe configurations?

A: Yes, both support DDR5 memory over a Twelve-channel bus with 576.0 GB/s bandwidth and provide Gen 5 PCIe with 128 Lanes (CPU only). Both also support ECC memory.

Q: How many cores and threads does each processor have?

A: The 9555P has 64 cores and 128 threads, while the 9565 has 72 cores and 144 threads.

Q: Which CPU has a larger L3 cache?

A: The 9565 has 384 MB of shared L3 cache, which is significantly larger than the 9555P’s 256 MB.

Where Each One Wins

The AMD EPYC 9555P is the winner in most categories, particularly those related to general-purpose integer work and data handling. The data shows it is the better choice for `passmark_integer_math` (14.4% ahead), `passmark_data_encryption` (9.8% ahead), `passmark_physics` (10.4% ahead), and `passmark_random_string_sorting` (11.6% ahead). It also narrowly wins all Cinebench tests and the `passmark_single_thread` test (0.8% ahead). This pattern suggests a processor that excels at database operations, encryption/decryption tasks, and general server logic that relies on high clock speeds and efficient integer execution. If your workload is transactional or involves heavy sorting, the 9555P’s scores are the strongest indicator of success.

The AMD EPYC 9565 is the clear winner in a narrow but critical set of workloads. Its 52.3% victory in `passmark_find_prime_numbers` is the standout, pointing to unusual strength in mathematical algorithms and potentially in cryptography or scientific computing that involves prime factorization. The 14% lead in `passmark_extended_instructions` indicates it handles complex instruction sets (like AVX-512 or similar) with far greater efficiency. The 12.6% lead in `passmark_floating_point_math` confirms its superiority in scientific simulations, 3D rendering, and machine learning inference that relies on floating-point computations. For these specific tasks, the 9565’s larger L3 cache and additional cores provide a measurable advantage despite its lower clock speeds.

Specification Differences

The core specifications that differ between the two processors are straightforward. The 9555P has 64 cores and 128 threads, while the 9565 has 72 cores and 144 threads. The base clock is 3.20 GHz on the 9555P versus 3.15 GHz on the 9565. The boost clock is 4.40 GHz on the 9555P versus 4.30 GHz on the 9565. The TDP is 360 W for the 9555P and 400 W for the 9565. The transistor count is 66,520 million for the 9555P and 99,780 million for the 9565. The die configuration is 8x 70.6 mm² for the 9555P and 12x 70.6 mm² for the 9565. The L3 cache is 256 MB (shared) for the 9555P and 384 MB (shared) for the 9565. The launch MSRP for the 9555P is $7983, and for the 9565 it is $10486. The part numbers are 100-000001523 for the 9555P and 100-000001447 for the 9565. All other fields—manufacturer, socket, architecture, process node, memory support, PCIe lanes, integrated graphics (none), market segment, and production status—are identical.