AMD EPYC 9355

Platform and Compatibility

The AMD EPYC 9355 is built for the EPYC 9005 series platform, utilizing the AMD Socket SP5. This socket is the foundation for the entire Turin generation, which means a single server platform can accommodate a wide range of processor options. The architecture is Zen 5, with the codename "Turin," and the processor is manufactured on TSMC's 4 nm process node. This node represents a significant step in transistor density, allowing for the integration of 66,520 million transistors across a multi-chiplet design with a die size of 8x 70.6 mm².

Memory support is comprehensive for high-end server workloads. The EPYC 9355 supports DDR5 memory across a twelve-channel memory bus, providing a theoretical memory bandwidth of 576.0 GB/s. This is a critical specification for data-intensive applications, as memory bandwidth often dictates performance in database, virtualization, and high-performance computing scenarios. The processor also supports ECC memory, which is standard for server platforms where data integrity is non-negotiable. For expansion and I/O, the chip provides PCIe Gen 5 with 128 lanes available from the CPU. This high lane count allows for extensive connectivity, including multiple high-speed network interfaces, storage controllers, and accelerators without needing a separate switch chip.

The upgrade path is straightforward due to the shared SP5 socket across the EPYC 9005 family. Systems designed for this socket can typically accommodate a range of processors from the same generation, offering flexibility for future scaling. The processor is not multiplier unlocked, indicating it is intended for fixed-configuration server deployments rather than enthusiast overclocking. The production status is active, and the release date was 2024-10-09, placing it in the current generation of server hardware. The part number is 100-000001148.

Power and Thermals

The EPYC 9355 carries a TDP of 280 watts. This places it in the higher power envelope of server processors, though it is not at the absolute top of the range for the EPYC 9005 series. A 280W TDP class demands a serious cooling solution. In a typical rack-mount server, this implies a high-performance active heat sink with multiple heat pipes and a high-static-pressure fan, or a direct-to-chip liquid cooling loop in dense deployments. The thermal design assumes adequate airflow through the chassis, and system integrators must ensure that the surrounding components, such as VRMs and memory, are also properly cooled to sustain full-load operation.

The power characteristics are directly tied to the core count and clock speeds. With 32 cores and 64 threads running at a base clock of 3.55 GHz and a boost clock of 4.40 GHz, the 280W TDP represents the sustained power draw under heavy all-core workloads. In practice, the processor will draw less power during lighter tasks, but the cooling system must be sized for the worst-case thermal output. The 4 nm process helps mitigate power consumption per transistor, but the sheer scale of the chip—256 MB of shared L3 cache and 128 PCIe Gen 5 lanes—contributes to the overall power budget. Benchmark results indicate that this power envelope is justified by the performance on offer, but it is a key consideration for data center power and cooling infrastructure planning. No specific cooler specifications are provided in the data, so the recommendation is simply a capable air or liquid cooler designed for 280W-class server processors.

Benchmark Performance

The benchmark data for the EPYC 9355 is notably sparse in the fact pack. The average benchmark score is reported as 0, and the percentile versus all CPUs is 50. This is an unusual data point, suggesting that the processor has not yet been subjected to the standard benchmark suite used by this database, or that the results are pending. The nearest rivals list is empty, and the benchmark scores array is also empty. This makes a direct numerical performance comparison impossible from the provided data alone.

However, the core specifications allow for a reasonable qualitative assessment. With 32 cores and 64 threads, the EPYC 9355 is positioned for heavy parallel workloads. The boost clock of 4.40 GHz is high for a server chip, which bodes well for lightly threaded tasks. The 256 MB L3 cache is enormous, designed to keep frequently accessed data close to the cores, reducing latency and improving throughput for large working sets. The twelve-channel DDR5 memory interface further supports this, providing the data feed necessary to keep 32 cores busy.

Given the lack of benchmark scores, it is not possible to state a specific performance delta against any rival. The percentile rank of 50 is ambiguous without a score distribution. It could indicate that the processor sits in the middle of the database's tested CPUs, but with no score, this is not a meaningful metric. The data suggests that the EPYC 9355 is a capable high-end server processor, but the benchmark section must remain a placeholder until actual scores are populated. The instructions for this analysis require using only the facts in the pack, so no speculative comparisons can be made.

How It Compares

The nearest rivals list is empty, which precludes any direct comparison to specific competing models. The data pack provides no names, scores, or deltaPct values for rival processors. In the absence of this information, the EPYC 9355 cannot be positioned against other server CPUs in a quantitative manner.

Qualitatively, the processor's specifications place it in the high core-count, high-bandwidth segment of the server market. The 32-core count is a sweet spot for many enterprise workloads, offering a balance between per-core performance and parallel throughput. The 128 PCIe Gen 5 lanes are a distinguishing feature, allowing for massive I/O expansion. The 576.0 GB/s memory bandwidth is also a top-tier figure. Without rival data, the analysis must stop here; any further comparison would require external knowledge, which is prohibited. The benchmark database will need to populate the nearest rivals field before a meaningful competitive analysis can be written.

Single-Thread vs Multi-Thread Behavior

The EPYC 9355 presents a balanced profile between single-thread and multi-thread performance, dictated by its clock speeds and core configuration. The boost clock of 4.40 GHz is notably high for a 32-core server part, indicating that single-threaded performance is a priority. This is beneficial for workloads that have a serial component or that rely on low-latency responses, such as financial trading applications, certain database queries, and legacy software that is not fully multithreaded. The high boost clock, combined with the Zen 5 architecture's instructions-per-clock improvements, suggests strong performance on tasks that utilize one or a few cores.

Conversely, the multi-thread performance is driven by the 32 cores and 64 threads. The base clock of 3.55 GHz ensures that all cores can sustain a high frequency under full load, assuming adequate cooling and power delivery. The 256 MB L3 cache is a significant asset here, as it reduces the need to access main memory, which is often a bottleneck in multi-threaded workloads. The twelve-channel memory bus also helps, ensuring that the memory subsystem can keep up with the data demands of 64 threads.

The split between these two behaviors means the EPYC 9355 is versatile. For a virtualized server hosting many small VMs, the high core count provides ample isolation and parallelism, while the high boost clock ensures that each VM experiences responsive performance. For a high-performance computing workload, such as a finite element analysis or a molecular dynamics simulation, the multi-thread capabilities shine, with the large cache and memory bandwidth enabling efficient scaling. The data indicates that this processor does not sacrifice single-thread performance for core count, making it a strong generalist in the server segment. The lack of benchmark scores prevents a numerical breakdown of this behavior, but the architectural specifications support this balanced interpretation.

FAQ

Q: What socket does the AMD EPYC 9355 use?

A: The AMD EPYC 9355 uses AMD Socket SP5, which is the standard socket for the EPYC 9005 series (Turin) processors.

Q: How much L3 cache does the EPYC 9355 have?

A: The EPYC 9355 has 256 MB of shared L3 cache. Additionally, it has 80 KB of L1 cache per core and 1 MB of L2 cache per core.

Q: What is the memory bandwidth of this processor?

A: The processor supports DDR5 memory across a twelve-channel memory bus, providing a theoretical memory bandwidth of 576.0 GB/s. It also supports ECC memory.

Q: How many PCIe lanes does the EPYC 9355 provide?

A: The EPYC 9355 provides 128 PCIe Gen 5 lanes directly from the CPU. This is exclusive of any additional lanes from the chipset.

Q: What is the TDP of the EPYC 9355?

A: The TDP of the EPYC 9355 is 280 watts. This requires a server-grade cooling solution designed for that thermal envelope.

Q: What is the launch MSRP of the EPYC 9355?

A: The launch MSRP is $3694. This was set at the time of release on 2024-10-09.