AMD EPYC 9755

The AMD EPYC 9755 is a 128-core, 256-thread server processor built on the Zen 5 architecture, codenamed Turin, and manufactured on TSMC's 4 nm process node. It is designed for the highest-density server and workstation workloads, holding a 100th percentile ranking among all CPUs in the benchmark database, which places it at the very top of the performance hierarchy.

Benchmark Performance

The benchmark data for the EPYC 9755 shows a processor that dominates in multi-threaded scenarios while maintaining competitive single-thread performance. In Cinebench R23, the multi-core score reaches 141,378 points, while the single-core score is 19,959. The ratio between these scores—roughly 7.1x—indicates the scaling efficiency of the 128-core design, though it also highlights the inherent limits of multi-core scaling in this workload.

The Cinebench R20 results follow a similar pattern, with a multi-core score of 59,378 and a single-core score of 8,382. The Cinebench R15 results show 14,250 in multi-core and 2,011 in single-core. Across all three Cinebench versions, the single-core scores are remarkably high for a server part, suggesting that the Zen 5 architecture delivers strong instruction-level parallelism and high clock speeds even with 128 cores active.

PassMark results provide a broader view of workload-specific performance. The multithread score is 166,328, while the single-thread score is 3,503. In data compression, the score is 4,517,407, and in data encryption, it is 284,927. Extended instructions score 303,321, floating-point math scores 922,900, and integer math scores 1,549,946. The find prime numbers test, which is often memory-latency sensitive, scores 2,047. The physics test scores 27,806, and random string sorting scores 571,185.

The average benchmark score across all tests is 505,778. Against its nearest rivals, the EPYC 9755 sits in a tight competitive cluster. It trails the AMD EPYC 9965 by 15%, with the 9965 achieving an average score of 595,264. It also trails the AMD EPYC 9845 by 3.4%, which scores 523,613. However, it leads the AMD EPYC 9745 by 18.7% (425,973) and the AMD Ryzen Threadripper PRO 9995WX by 24.5% (406,395). This positioning means the EPYC 9755 is not the absolute fastest in its immediate family, but it is significantly ahead of lower-core-count siblings and the flagship Threadripper PRO.

Platform and Compatibility

The EPYC 9755 uses the AMD Socket SP5 platform, which is the enterprise socket for AMD's latest EPYC generations. The processor is based on the Zen 5 architecture with the codename Turin, placing it in the EPYC (Zen 5 (Turin)) generation. The package consists of 16 chiplets, each with a die size of 70.6 mm², totaling 133,040 million transistors on the 4 nm TSMC process.

Memory support is DDR5 with a twelve-channel memory bus. The theoretical memory bandwidth is 576.0 GB/s, which is essential for feeding the 128 cores. ECC memory is supported, which is a standard requirement for server reliability. The processor provides 128 PCIe Gen 5 lanes from the CPU only, which allows for extensive high-speed I/O connectivity for accelerators, NVMe storage, and network interfaces.

The production status is active, with a release date of October 9, 2024. The launch MSRP is $12984. The multiplier is not unlocked, meaning the processor is not intended for overclocking; it operates at a base clock of 2.70 GHz and a boost clock of 4.10 GHz. The cache hierarchy is substantial: 80 KB of L1 per core, 1 MB of L2 per core, and a shared L3 cache of 512 MB. This large L3 cache is critical for workloads that share data across many cores, reducing the need to access main memory.

Power and Thermals

The EPYC 9755 has a TDP of 500 watts. This is a very high power envelope, categorizing the processor in the top tier of air-coolable server parts, though it will require robust cooling solutions. The data does not specify a cooler type, but the 500 W TDP class implies that standard low-profile server heatsinks will be insufficient; high-performance air coolers or liquid cooling are necessary to maintain sustained boost clocks.

The 4 nm process node helps mitigate power density, but with 128 cores operating at a 4.10 GHz boost clock, the thermal load is significant. The 500 W TDP also dictates power supply requirements and chassis airflow design. In a dual-socket configuration, the combined thermal output would be substantial, requiring careful data center planning. The high TDP is a trade-off for the extreme core count and the 512 MB L3 cache, which itself consumes power to maintain.

How It Compares

vs. AMD EPYC 9845: The EPYC 9755 trails the 9845 by 3.4% in average benchmark score. This is a narrow margin, indicating that the 9845, which has a lower core count, achieves better per-core performance or higher sustained clocks in the benchmark suite. The 9755's advantage in core count does not fully translate to a lead in these specific tests, suggesting that the 9845 may have a higher boost clock or better memory latency characteristics.

vs. AMD EPYC 9745: The EPYC 9755 leads the 9745 by 18.7%. This is a substantial gap that reflects the core count difference, as the 9745 is a lower-tier part in the same Turin family. The 18.7% advantage is consistent with the scaling expected from additional cores, though the 9755 also likely benefits from higher cache capacity.

vs. AMD EPYC 9965: The EPYC 9755 trails the 9965 by 15%. The 9965 is the top performer in this rival group, and the 15% deficit is significant. This suggests that the 9965 either has a higher core count, higher clocks, or better memory bandwidth utilization. The 9755 is positioned below the flagship in the same generation.

vs. AMD Ryzen Threadripper PRO 9995WX: The EPYC 9755 leads this workstation processor by 24.5%. The Threadripper PRO 9995WX is a high-end desktop part, but the EPYC 9755's server-oriented design with more cores and memory channels provides a clear performance advantage in the multi-threaded benchmarks that dominate the average score.

Single-Thread vs Multi-Thread Behavior

The split between single-thread and multi-thread performance reveals the EPYC 9755's dual personality. In Cinebench R23, the single-core score of 19,959 is high in absolute terms, but the multi-core score of 141,378 shows that the processor scales to roughly 7.1 times the single-core performance. This scaling factor is below the theoretical 128x maximum, which is expected due to memory bandwidth limits and thread synchronization overheads.

The PassMark single-thread score of 3,503 is competitive with high-end desktop processors, indicating that the Zen 5 cores are not compromised for the sake of core count. The base clock of 2.70 GHz with a boost of 4.10 GHz allows for strong single-thread responsiveness when few threads are active.

For real workloads, this means the EPYC 9755 excels in tasks that can utilize many threads, such as virtualization, large-scale data processing, and scientific simulations. The data compression score of 4,517,407 and integer math score of 1,549,946 are particularly strong, suggesting excellent throughput for database and analytics workloads. However, the find prime numbers score of 2,047 is relatively low, which may indicate sensitivity to memory latency in certain algorithmic patterns, despite the 512 MB L3 cache.

The single-thread performance ensures that legacy applications with limited thread parallelism still run well, but the processor's value is clearly in its multi-threaded capabilities. The 256 threads provide enormous parallelism for cloud workloads and high-performance computing, where the 576.0 GB/s memory bandwidth can be saturated by many concurrent memory streams.

FAQ

Q: What is the core and thread count of the AMD EPYC 9755?

A: The EPYC 9755 has 128 cores and 256 threads.

Q: What is the launch MSRP of the EPYC 9755?

A: The launch MSRP is $12984.

Q: What memory type and bus width does the EPYC 9755 support?

A: It supports DDR5 memory with a twelve-channel memory bus, providing 576.0 GB/s of bandwidth. ECC memory is supported.

Q: How does the EPYC 9755 compare to the AMD EPYC 9965 in average benchmark score?

A: The EPYC 9755 trails the EPYC 9965 by 15%, with average scores of 505,778 and 595,264, respectively.

Q: What is the TDP of the EPYC 9755 and what does it imply for cooling?

A: The TDP is 500 watts, which necessitates a robust cooling solution, likely high-end air cooling or liquid cooling, to maintain performance.

Q: What is the L3 cache size on the EPYC 9755?

A: The L3 cache is 512 MB, shared across all cores.

Q: Does the EPYC 9755 have an unlocked multiplier?

A: No, the multiplier is not unlocked, so the processor is not intended for overclocking.