AMD EPYC 9555P vs AMD EPYC 9845 Comparison

The AMD EPYC 9845 and AMD EPYC 9555P are both active members of the EPYC 9005 series, built on the Zen 5 architecture and sharing the AMD Socket SP5 platform. Despite their common lineage, the benchmark data shows a clear performance hierarchy, with the 9845 dominating in nearly every recorded test while the 9555P claims a notable victory in single-threaded workloads. The following analysis breaks down the recorded measurements, architectural differences, and use-case implications.

Head-to-Head Benchmarks

The head-to-head results are overwhelmingly one-sided. Across the 17 recorded benchmark comparisons, the AMD EPYC 9845 wins 15, while the AMD EPYC 9555P takes 2. The magnitude of the 9845's victories varies widely depending on the workload type.

In the Cinebench suite, the 9845 consistently leads by a margin of 12.9%. This applies uniformly across all six tests: Cinebench R15 multi-core (13107 vs 11610), R15 single-core (1850 vs 1638), R20 multi-core (54615 vs 48378), R20 single-core (7710 vs 6829), R23 multi-core (130037 vs 115186), and R23 single-core (18358 vs 16261). The consistent 12.9% delta across both single and multi-threaded tests indicates that the 9845's advantage here is not purely core-count driven; it also holds a per-core performance edge in these rendering workloads.

The PassMark suite reveals a different story, with the 9845's advantage scaling dramatically in heavily parallel workloads. The largest deltas appear in integer math (1687531 vs 787106, a 114.4% advantage), floating-point math (978377 vs 486407, a 101.1% advantage), and data encryption (296808 vs 148896, a 99.3% advantage). These tests nearly double the 9555P's output, reflecting the 9845's massive core count advantage. Data compression shows a 77.3% lead (4680013 vs 2639400), random string sorting a 91.9% lead (538060 vs 280398), and extended instructions a 64.7% lead (314798 vs 191082).

The 9845 also wins in mixed-thread workloads, though by smaller margins. PassMark multi-thread shows a 23.8% lead (152985 vs 123576), physics a 26.9% lead (19631 vs 15474), and find prime numbers a 17.6% lead (1255 vs 1067). These smaller deltas suggest that the 9555P's higher clock speeds partially compensate for its fewer cores in latency-sensitive tasks.

The one area where the 9555P wins is PassMark single-thread: 3410 vs 3144, a 7.8% advantage. This appears in both the `passmark_single_thread` and `passmark_singlethread` entries, confirming the result. The 9555P's higher boost clock and base clock give it a genuine single-core edge, which matters for lightly threaded applications.

The Verdict

The data indicates that the AMD EPYC 9845 is the superior choice for workloads that scale with core count and memory bandwidth, which is the majority of server and workstation tasks. Its 114.4% lead in integer math and 101.1% lead in floating-point math are decisive for scientific computing, database processing, and compilation workloads. The 99.3% advantage in data encryption is particularly relevant for security-focused infrastructure. The 9845 also maintains a 12.9% lead in all Cinebench tests, meaning even single-threaded rendering performance is better on the 9845, despite the 9555P's clock advantage.

The AMD EPYC 9555P is the correct choice when single-threaded performance is the priority and core count is less critical. Its 7.8% lead in PassMark single-thread is the only benchmark where it beats the 9845. This makes it suitable for workloads that are heavily serialized, such as certain legacy applications, some financial modeling, or interactive database queries that cannot be parallelized. The 9555P also offers a significantly lower launch MSRP of $7983 compared to the 9845's $13564, though pricing considerations are secondary to raw capability in this analysis.

Looking at the broader competitive landscape, the 9845 sits at the 100th percentile of all CPUs, with an average benchmark score of 523613. Its nearest rivals include the AMD EPYC 9755 (3.5% behind), the AMD EPYC 9965 (15.6% ahead), the AMD EPYC 9745 (22.9% behind), and the AMD Ryzen Threadripper PRO 9995WX (27.1% behind). The 9555P, at the 99th percentile, has an average score of 287066 and sits in a tighter competitive cluster: the Intel Xeon 696X is only 0.3% behind, the AMD EPYC 9565 is 0.6% behind, the Intel Xeon 6780E is 2.4% behind, and the AMD Ryzen Threadripper 9970X is 2.6% behind.

Architecture Differences

The two processors share the same Zen 5 architecture and the Turin codename, but they are built on different process nodes. The AMD EPYC 9845 uses a 3 nm process, while the AMD EPYC 9555P uses a 4 nm process, both fabbed by TSMC. The 9845's generation is listed as "EPYC (Zen 5c (Turin))", while the 9555P is "EPYC (Zen 5 (Turin))", indicating the 9845 uses the dense "c" variant of the Zen 5 cores.

Core and thread counts differ substantially: the 9845 has 160 cores and 320 threads, while the 9555P has 64 cores and 128 threads. This is a 2.5x difference in core count. The 9845 compensates for its denser core layout with a lower base clock of 2.10 GHz and a boost clock of 3.70 GHz, while the 9555P runs at 3.20 GHz base and 4.40 GHz boost. The 9555P's higher clocks explain its single-thread victory.

Cache configuration differs as well. Both share the same per-core L1 (80 KB) and L2 (1 MB) cache, but the L3 cache is larger on the 9845: 320 MB shared versus 256 MB shared on the 9555P. The 9555P's transistor count is listed at 66,520 million across a die size of 8x 70.6 mm², while the 9845 does not have recorded transistor or die size data.

Memory support is identical: both use DDR5, twelve-channel memory buses, and have a memory bandwidth of 576.0 GB/s. ECC memory is supported on both. PCIe connectivity is also the same: Gen 5 with 128 lanes (CPU only). Both have no integrated graphics and are marked for the Server/Workstation market segment. Neither has an unlocked multiplier.

FAQ

Q: Which processor has more cores?

A: The AMD EPYC 9845 has 160 cores and 320 threads, while the AMD EPYC 9555P has 64 cores and 128 threads.

Q: Is the AMD EPYC 9845 faster in every benchmark?

A: No. The 9845 wins 15 of 17 benchmark comparisons, but the 9555P wins the PassMark single-thread test by 7.8% (3410 vs 3144).

Q: What is the single biggest performance gap between the two?

A: The largest delta is in PassMark integer math, where the 9845 leads by 114.4% (1687531 vs 787106).

Q: Do both processors support the same memory configuration?

A: Yes, both support DDR5 with a twelve-channel memory bus and 576.0 GB/s bandwidth, along with ECC memory.

Q: What process nodes do these processors use?

A: The 9845 uses a 3 nm process, while the 9555P uses a 4 nm process, both from TSMC.

Q: How do they compare in average benchmark score?

A: The 9845 has an average benchmark score of 523613, while the 9555P has an average of 287066.

Where Each One Wins

The AMD EPYC 9845 wins in all multi-threaded and heavily parallel workloads. Its 160 cores deliver 114.4% more integer math throughput, 101.1% more floating-point math throughput, 99.3% more encryption throughput, and 91.9% more random string sorting throughput. It also leads in data compression by 77.3% and extended instructions by 64.7%. For rendering, the 9845 leads all Cinebench tests by 12.9%, including single-core tests, meaning it is the better choice for both multi-frame and single-frame rendering tasks. Its 23.8% lead in PassMark multi-thread and 26.9% lead in physics make it the stronger option for simulation and physics-based workloads. The 9845 also wins in find prime numbers by 17.6%, a test that often reflects memory latency and cache performance.

The AMD EPYC 9555P wins only in PassMark single-thread, with a 7.8% advantage (3410 vs 3144). This is the sole metric where the 9555P's higher base and boost clocks (3.20 GHz and 4.40 GHz versus 2.10 GHz and 3.70 GHz) translate into a measurable victory. For workloads that are fundamentally single-threaded and cannot be parallelized, such as certain scripting engines, legacy single-core applications, or interactive command-line tools, the 9555P offers better responsiveness. The 9555P's position in the 99th percentile versus the 9845's 100th percentile also confirms that it is a top-tier processor in its own right, just not at the absolute performance ceiling.

Specification Differences

The following fields differ between the two processors:

• Cores: 160 (9845) vs 64 (9555P)
• Threads: 320 (9845) vs 128 (9555P)
• Base Clock: 2.10 GHz (9845) vs 3.20 GHz (9555P)
• Boost Clock: 3.70 GHz (9845) vs 4.40 GHz (9555P)
• TDP: 390 W (9845) vs 360 W (9555P)
• Process Node: 3 nm (9845) vs 4 nm (9555P)
• Transistors: Not recorded (9845) vs 66,520 million (9555P)
• Die Size: Not recorded (9845) vs 8x 70.6 mm² (9555P)
• L3 Cache: 320 MB shared (9845) vs 256 MB shared (9555P)
• Launch MSRP: $13564 (9845) vs $7983 (9555P)
• Part Number: 100-000001458 (9845) vs 100-000001523 (9555P)

All other specifications are identical: both use Zen 5 architecture, the Turin codename, AMD Socket SP5, 80 KB per-core L1 cache, 1 MB per-core L2 cache, DDR5 memory support, twelve-channel memory bus, 576.0 GB/s memory bandwidth, ECC memory support, Gen 5 PCIe with 128 CPU-only lanes, no integrated graphics, the Server/Workstation market segment, and an active production status with a release date of 2024-10-09.