AMD EPYC 9384X vs AMD Ryzen 9 PRO 9955 Comparison

The AMD EPYC 9384X and AMD Ryzen 9 PRO 9955 represent two completely different philosophies in CPU design. One is a massive 32-core server processor built to crush multi-threaded workloads, while the other is a 12-core workstation chip that emphasizes raw single-core speed. The data here shows a stark divide: the EPYC dominates in nearly every parallel test, but the Ryzen wins decisively where single-thread latency matters most.

Head-to-Head Benchmarks

The benchmark results are overwhelmingly one-sided. Across the eleven shared Passmark tests, the EPYC 9384X wins nine, while the Ryzen 9 PRO 9955 claims only two. The margins tell the real story. In `passmark_physics`, the EPYC scores 9332 against the Ryzen’s 3332, a massive 180.1% advantage. This is the largest gap between the two, and it highlights how the EPYC’s 32 cores and 64 threads simply overwhelm the Ryzen’s 12 cores and 24 threads in a physics simulation workload.

The EPYC also shows huge leads in data-heavy tasks. In `passmark_data_encryption`, it scores 72631 versus 33754, a 115.2% difference. Similarly, `passmark_random_string_sorting` sees the EPYC at 119440 against 71928, a 66.1% margin. Integer and floating-point math follow the same pattern: the EPYC posts 297833 in `passmark_integer_math` (63.4% ahead of 182312) and 174630 in `passmark_floating_point_math` (43.7% ahead of 121509). Even `passmark_data_compression` shows a 63.6% lead, with the EPYC scoring 1119983 to the Ryzen’s 684470.

The EPYC’s win in `passmark_multithread` is 69665 versus 54866, a 27% advantage. That is a solid lead, but not as dramatic as the physics or encryption results. The same goes for `passmark_extended_instructions` (74363 vs 54903, a 35.4% lead) and `passmark_find_prime_numbers` (596 vs 461, a 29.3% lead).

Now for the Ryzen’s two wins. In `passmark_single_thread`, the Ryzen 9 PRO 9955 scores 4597, which is 34.4% higher than the EPYC’s 3015. This is the exact same result in `passmark_singlethread`, confirming the Ryzen’s dominance in single-core performance. This is not a small margin; it is a crushing defeat for the EPYC in this specific metric. The Ryzen’s 5.40 GHz boost clock versus the EPYC’s 3.90 GHz boost clock explains this gap.

Looking at the broader picture, the EPYC’s average benchmark score is 120427, placing it in the 97th percentile of all CPUs. The Ryzen’s average is 110612, also in the 97th percentile. The EPYC’s nearest rival is the Intel Xeon w7-3565X, which is 1.8% behind, and the AMD EPYC 7642, which is 2.9% ahead. The Ryzen’s closest competitors include the Intel Xeon w7-2595X (1.8% behind) and the AMD Ryzen 9 9850HX (3.9% ahead). Both chips are firmly in top-tier territory, but their strengths are polar opposites.

Where Each One Wins

The EPYC 9384X is the clear winner for any workload that scales with core count. The physics test, with its 180.1% lead, points to simulation and scientific computing as primary use cases. Data encryption and compression, where the EPYC leads by 115.2% and 63.6% respectively, suggest it is excellent for database workloads, file servers, and any task involving heavy data manipulation. The integer and floating-point math results (63.4% and 43.7% leads) further cement this as a compute monster for rendering, financial modeling, and engineering simulations.

The Ryzen 9 PRO 9955 wins where latency matters more than throughput. Its 34.4% lead in single-thread performance makes it better suited for applications that rely on fast response times, such as interactive design work, legacy single-threaded software, or tasks where the main bottleneck is a single core’s speed. The Ryzen’s higher base clock (3.40 GHz vs 3.10 GHz) and boost clock (5.40 GHz vs 3.90 GHz) give it a clear edge in these scenarios. However, its wins are limited to just these two tests, meaning its overall multi-threaded capability is far behind.

Architecture Differences

The architectural divide is significant. The EPYC 9384X is based on Zen 4, with the codename Genoa-X, and belongs to the EPYC 9004 series. It is built on a 5 nm process at TSMC, with 90,160 million transistors spread across 8 dies, each measuring 72 mm². The Ryzen 9 PRO 9955 uses Zen 5, with the codename Granite Ridge, from the Ryzen 9000 series. It is built on a more advanced 4 nm process, also at TSMC, but with only 16,630 million transistors on 2 dies of 70.6 mm² each. This process advantage likely contributes to the Ryzen’s higher clock speeds.

Cache configurations differ drastically. The EPYC has 64 KB of L1 per core, 1 MB of L2 per core, and a massive 768 MB of shared L3 cache. This is an enormous amount of L3, designed to feed its 32 cores in data-heavy server workloads. The Ryzen has 80 KB of L1 per core and 1 MB of L2 per core, but only 64 MB of L3. That is a 12x difference in L3 capacity, which explains the EPYC’s dominance in data compression and encryption tasks.

Memory support also diverges. The EPYC uses DDR5 memory over a twelve-channel bus, delivering 460.8 GB/s of bandwidth. The Ryzen also uses DDR5, but over a dual-channel bus, providing only 89.6 GB/s. This five-fold difference in memory bandwidth is critical for workloads that stream large datasets. Both support ECC memory, but the EPYC’s memory subsystem is clearly built for enterprise-scale demands.

Specification Differences

The core and thread counts are the most obvious difference: the EPYC has 32 cores and 64 threads, while the Ryzen has 12 cores and 24 threads. The EPYC’s base clock is 3.10 GHz, and its boost clock is 3.90 GHz. The Ryzen’s base clock is 3.40 GHz, and its boost clock is 5.40 GHz. The TDP reflects this: the EPYC draws 320 watts, while the Ryzen is rated at 120 watts.

The sockets are incompatible. The EPYC uses AMD Socket SP5, while the Ryzen uses AMD Socket AM5. The PCIe lanes also differ: the EPYC offers Gen 5 with 128 lanes (CPU only), whereas the Ryzen provides Gen 5 with 24 lanes (CPU only). The Ryzen includes integrated Radeon Graphics, while the EPYC has no integrated graphics. The EPYC was released on 2023-06-12 and has a launch MSRP of $5529. The Ryzen’s release date is 2026-06-29, and it has no launch MSRP listed. The EPYC’s part number is not specified, while the Ryzen’s is 100-000001971. Neither chip has an unlocked multiplier.

FAQ

Q: Which CPU is faster in single-threaded workloads?

A: The AMD Ryzen 9 PRO 9955 is significantly faster, scoring 4597 in `passmark_single_thread` compared to the EPYC 9384X’s 3015, a 34.4% advantage.

Q: How much better is the EPYC in multi-threaded performance?

A: The EPYC leads by 27% in `passmark_multithread` (69665 vs 54866) and by 180.1% in `passmark_physics` (9332 vs 3332). The EPYC also wins in every other multi-threaded test in the shared benchmark suite.

Q: What is the difference in cache size?

A: The EPYC has 768 MB of shared L3 cache, while the Ryzen has 64 MB. The EPYC also has 64 KB of L1 per core versus 80 KB on the Ryzen, but the Ryzen has a smaller total L1 footprint due to fewer cores.

Q: Do both CPUs support ECC memory?

A: Yes, both the EPYC 9384X and the Ryzen 9 PRO 9955 support ECC memory. However, the EPYC uses a twelve-channel memory bus with 460.8 GB/s bandwidth, while the Ryzen uses a dual-channel bus with 89.6 GB/s.

Q: Which CPU has a higher boost clock speed?

A: The Ryzen 9 PRO 9955 has a boost clock of 5.40 GHz, which is substantially higher than the EPYC 9384X’s 3.90 GHz boost clock.

Q: Are these CPUs on the same socket?

A: No. The EPYC 9384X uses AMD Socket SP5, while the Ryzen 9 PRO 9955 uses AMD Socket AM5. They are not interchangeable.

The Verdict

The data is unambiguous. If your workload is heavily parallelized, the AMD EPYC 9384X is the only choice. It wins 9 of 11 head-to-head tests, with margins exceeding 100% in physics and encryption. Its 32 cores, 64 threads, 768 MB of L3 cache, and twelve-channel memory bandwidth make it a server-class part for rendering, simulation, and data processing. The 97th percentile ranking and average score of 120427 confirm its position among the fastest CPUs available.

The AMD Ryzen 9 PRO 9955 is for a different user. Its 34.4% single-thread advantage and 5.40 GHz boost clock make it far more responsive for latency-sensitive tasks. It is also a 97th percentile CPU, but its strengths lie elsewhere. If you need fast interactive performance and can accept fewer cores, the Ryzen is the better fit. If you need raw throughput, the EPYC’s massive core count and cache will leave the Ryzen far behind in any multi-threaded benchmark. The choice comes down to what you value: the EPYC’s overwhelming parallel power or the Ryzen’s unmatched single-core speed.