AMD EPYC 9355P vs AMD Ryzen 9 PRO 9965X3D Comparison

FAQ

Q: Which processor has more cores and threads?

A: The AMD EPYC 9355P has 32 cores and 64 threads, while the AMD Ryzen 9 PRO 9965X3D has 16 cores and 32 threads. The EPYC offers double the core and thread count.

Q: Which processor has a higher single-thread benchmark score?

A: The AMD Ryzen 9 PRO 9965X3D wins the PassMark single-thread test with a score of 4614, compared to the EPYC 9355P's 3747. That is an 18.8% advantage for the Ryzen in this specific metric.

Q: How much faster is the EPYC 9355P in multi-threaded workloads?

A: In the PassMark multithread test, the EPYC 9355P scores 96603 versus the Ryzen 9 PRO 9965X3D's 68225. This represents a 41.6% lead for the EPYC processor.

Q: Which chip has a larger L3 cache?

A: The AMD EPYC 9355P has 256 MB of shared L3 cache. The AMD Ryzen 9 PRO 9965X3D has 128 MB of L3 cache. The EPYC's cache is double the size.

Q: What are the socket requirements for each processor?

A: The AMD EPYC 9355P uses AMD Socket SP5, which is designed for server/workstation platforms. The AMD Ryzen 9 PRO 9965X3D uses AMD Socket AM5, the mainstream desktop socket.

Q: Do both processors support ECC memory?

A: Yes, both the EPYC 9355P and the Ryzen 9 PRO 9965X3D support ECC memory.

Architecture Differences

The AMD EPYC 9355P and AMD Ryzen 9 PRO 9965X3D both originate from AMD's Zen 5 architecture, but they are tailored for vastly different platforms. The EPYC 9355P is part of the EPYC 9005 series, codenamed Turin, and is fabricated on a 4 nm process at TSMC. It packs 66,520 million transistors across a complex of eight chiplets, each with a die size of 70.6 mm². The Ryzen 9 PRO 9965X3D, on the other hand, is a Granite Ridge part from the 9000 series, also built on TSMC's 4 nm node but with a total of 16,630 million transistors spread across two chiplets of 70.6 mm² each.

The most significant architectural divergence is in the memory subsystem. The EPYC 9355P features a twelve-channel memory bus, delivering a massive memory bandwidth of 576.0 GB/s. The Ryzen 9 PRO 9965X3D is limited to a dual-channel bus, offering a comparatively modest 89.6 GB/s. This bandwidth disparity has direct implications for memory-intensive server workloads.

PCIe connectivity also differs substantially. The EPYC 9355P provides 128 PCIe Gen 5 lanes (CPU only), whereas the Ryzen 9 PRO 9965X3D offers 24 PCIe Gen 5 lanes (CPU only). This makes the EPYC a clear choice for systems needing vast I/O expansion, such as high-speed storage arrays or multiple GPU accelerators.

Another key difference is the integrated graphics. The EPYC 9355P has no integrated graphics (N/A), meaning a discrete GPU is mandatory for display output. The Ryzen 9 PRO 9965X3D includes Radeon Graphics, allowing for basic display functionality without a separate graphics card. The cache hierarchies also differ: both share the same 80 KB L1 and 1 MB L2 per core, but the EPYC 9355P's L3 is 256 MB shared, while the Ryzen 9 PRO 9965X3D has 128 MB.

Head-to-Head Benchmarks

The benchmark data shows a clear pattern: the EPYC 9355P dominates in nearly every multi-threaded and compute-intensive workload, while the Ryzen 9 PRO 9965X3D only wins in single-thread performance.

The most lopsided result comes in the PassMark physics test. The EPYC 9355P scores 13515, against the Ryzen 9 PRO 9965X3D's 4801. This is an enormous 181.5% advantage for the EPYC, reflecting the benefit of having double the cores and threads in a workload that scales well with parallel execution.

In PassMark integer math, the EPYC 9355P scores 412067 versus 237955 for the Ryzen. This translates to a 73.2% lead. The data encryption test shows the EPYC at 80961, which is 84.4% higher than the Ryzen's 43905. Similarly, the find prime numbers test shows the EPYC at 1044, a 74.3% improvement over the Ryzen's 599.

The floating-point math test continues the trend, with the EPYC 9355P scoring 256635 compared to the Ryzen's 157123, a 63.3% difference. Random string sorting, a memory-latency-sensitive workload, also goes to the EPYC, which scores 176697 versus 92886, a 90.2% lead. The extended instructions test shows a 52% advantage for the EPYC (107622 vs 70797).

The PassMark multithread score, which is a composite indicator of parallel performance, gives the EPYC 9355P a score of 96603, while the Ryzen 9 PRO 9965X3D scores 68225, a 41.6% difference. The data compression test shows a 59.7% win for the EPYC (1429976 vs 895563).

The sole bright spot for the Ryzen 9 PRO 9965X3D is the PassMark single-thread test. It scores 4614, which is 18.8% higher than the EPYC 9355P's 3747. This indicates that the Ryzen's higher base clock of 4.30 GHz and boost clock of 5.50 GHz provide a tangible advantage in lightly-threaded applications.

Overall, the EPYC 9355P wins 9 out of the 11 head-to-head benchmark comparisons, with the Ryzen 9 PRO 9965X3D taking the remaining 2 in the single-thread tests.

Specification Differences

The following table highlights the key specification differences between the two processors, based on the recorded data.

| Specification | AMD EPYC 9355P | AMD Ryzen 9 PRO 9965X3D |

| :--- | :--- | :--- |

| Series | EPYC 9005 series | 9000 series |

| Cores | 32 | 16 |

| Threads | 64 | 32 |

| Base Clock | 3.55 GHz | 4.30 GHz |

| Boost Clock | 4.40 GHz | 5.50 GHz |

| TDP | 280 W | 170 W |

| Socket | AMD Socket SP5 | AMD Socket AM5 |

| Codename | Turin | Granite Ridge |

| Transistors | 66,520 million | 16,630 million |

| Die Size | 8x 70.6 mm² | 2x 70.6 mm² |

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

| Memory Bus | Twelve-channel | Dual-channel |

| Memory Bandwidth | 576.0 GB/s | 89.6 GB/s |

| PCIe | Gen 5, 128 Lanes (CPU only) | Gen 5, 24 Lanes (CPU only) |

| Integrated Graphics | N/A | Radeon Graphics |

| Release Date | 2024-10-09 | 2026-06-29 |

| Launch MSRP | $2998 | N/A |

| Part Number | 100-000001521 | 100-000001999 |

The EPYC 9355P has a higher TDP at 280 W, compared to the Ryzen's 170 W, reflecting its larger core count and server-oriented design. The EPYC also has a much higher transistor count and a larger aggregate die area. The Ryzen 9 PRO 9965X3D has a significantly higher boost clock, which is a major factor in its single-thread performance win.

Where Each One Wins

The AMD EPYC 9355P is the clear choice for multi-threaded, compute-heavy server and workstation workloads. Its 32 cores and 64 threads provide a massive parallel throughput advantage. The benchmark data confirms this: it wins the multithread test by 41.6%, the physics test by 181.5%, and the integer math test by 73.2%. For applications like scientific simulation, data encryption, and financial modeling, the EPYC 9355P's performance is unmatched in this comparison. The twelve-channel memory bus and 576.0 GB/s of bandwidth are also critical for workloads that are memory-bound, such as large-scale data analysis. The 128 PCIe Gen 5 lanes provide the I/O flexibility required for enterprise storage and compute clusters. This processor is designed for a server platform, and the data shows it excels there.

The AMD Ryzen 9 PRO 9965X3D, with its higher boost clock and single-thread score, is better suited for tasks that rely on per-core performance. The 18.8% win in the single-thread test and the higher 4.30 GHz base clock make it a preferable option for legacy applications or workloads with limited parallelism. The presence of Radeon integrated graphics is also a practical benefit for systems that do not require a discrete GPU. Its lower TDP of 170 W also indicates a more power-efficient operation, which could be advantageous in a workstation environment where power density is a concern. However, the data shows it falls short in every multi-threaded test, making it a less compelling choice for any type of batch processing or heavy parallel load.