AMD EPYC 9355P vs Intel Xeon 676X Comparison

The AMD EPYC 9355P and Intel Xeon 676X are both 32-core server processors aimed at the same socket-less, high-core-count workstation segment. Both sit at the 98th percentile of all CPUs in the database, yet their benchmark profiles could not be more different. The data reveals a clear split: AMD dominates the majority of compute workloads, while Intel counters with a smaller set of specific wins. This analysis walks through the head-to-head results, explores where each part excels, and examines the architectural choices behind those numbers.

Head-to-Head Benchmarks

The most striking outcome is the sheer volume of AMD victories. Of the 16 benchmark comparisons, the EPYC 9355P wins 13, while the Xeon 676X takes only 3. The margins are not uniform; some are narrow, while others are decisive.

In Cinebench, the EPYC 9355P posts a clean sweep. Across R15, R20, and R23, the delta is remarkably consistent at 6.7% for multi-core tests and 6.8% for single-core tests. For instance, in Cinebench R23 multi-core, the AMD part scores 82,666 against Intel’s 77,447. This consistency suggests a fundamental per-core efficiency advantage rather than a workload-specific quirk. The R20 single-core result (4,901 vs 4,591) confirms that AMD’s advantage extends to lightly threaded tasks, not just all-core loads.

The PassMark suite tells a more nuanced story. AMD’s wins include data compression (5.5% ahead), data encryption (a massive 19.7% lead), extended instructions (2.3%), integer math (16.1%), multi-thread (6%), physics (an enormous 63.2% lead), and random string sorting (28.1%). The physics test is the single largest margin in the entire comparison, with the EPYC 9355P scoring 13,515 versus Intel’s 8,281. This points to a substantial advantage in simulation or physics-heavy workloads.

However, the Xeon 676X fights back in three specific areas. The most notable is floating-point math, where Intel leads by 9.5% (283,570 vs 256,635). This is a significant counter-punch, suggesting Intel’s AVX-512 implementation or FPU design handles this workload better. Additionally, the Xeon wins both single-thread tests, with PassMark single-thread scores of 4,015 versus 3,747, a 6.7% margin. This is interesting because AMD won the Cinebench single-core tests. The discrepancy implies the two processors have different strengths in different single-threaded applications.

Looking at the average benchmark scores, the EPYC 9355P holds a narrow aggregate lead. Its average is 160,358 against Intel’s 158,540, a 1.1% difference. This places the AMD part just behind the AMD EPYC 7663 (161,973) and the EPYC 9375F (162,497) in the rivals list, while the Xeon 676X sits ahead of the Intel Xeon 6745P (154,858) by 2.4%.

Where Each One Wins

The data suggests a clear use-case split. The EPYC 9355P is the general-purpose compute champion. Its wins span integer math, encryption, compression, sorting, and physics. For database workloads, data analytics, or any application that relies on hashing, compression, or string manipulation, the AMD part is consistently faster. The 19.7% lead in data encryption and 28.1% lead in random string sorting are particularly relevant for security-focused or data-intensive server roles.

The physics result deserves special attention. A 63.2% margin is not a minor difference; it indicates a fundamental architectural advantage in handling the specific instruction patterns of that benchmark. This could translate to faster performance in engineering simulation, computational fluid dynamics, or other physics-based modeling tasks, although the benchmark itself is synthetic.

The Xeon 676X carves out a narrower but important niche. Its floating-point math win (9.5%) makes it the better choice for workloads dominated by dense matrix operations, scientific computing, or financial modeling that relies heavily on FP arithmetic. The single-thread PassMark win (6.7%) also suggests that for specific legacy or lightly threaded applications, Intel’s higher boost clock can provide a tangible advantage.

Architecture Differences

The benchmark results become clearer when examining the underlying hardware. Both chips use 32 cores and 64 threads, but their designs diverge sharply.

The AMD EPYC 9355P is built on TSMC’s 4 nm process, while the Intel Xeon 676X uses Intel’s 5 nm node. AMD’s die is comprised of eight chiplets, each 70.6 mm², totaling a much smaller aggregate die area than Intel’s two large 598 mm² dies. This is a fundamental difference: AMD’s chiplet design allows for better yields and lower power per die, while Intel’s monolithic approach on a larger node may explain its higher boost clock.

Clock speeds are a key differentiator. The Xeon 676X has a lower base clock (2.80 GHz vs 3.55 GHz) but a higher boost clock (4.90 GHz vs 4.40 GHz). This explains the single-thread PassMark win for Intel, as it can ramp a single core higher. However, the EPYC 9355P’s higher base clock gives it an advantage in sustained all-core workloads, as seen in the Cinebench multi-core results.

Cache hierarchies are also distinct. AMD provides 256 MB of shared L3 cache, while Intel offers 144 MB. AMD’s L1 is 80 KB per core and L2 is 1 MB per core, whereas Intel has a larger 112 KB L1 and 2 MB L2 per core. The massive L3 advantage for AMD likely contributes to its wins in compression and encryption, where larger working sets can be cached.

Memory architecture differs significantly. The EPYC 9355P supports twelve-channel DDR5, delivering a theoretical bandwidth of 576.0 GB/s. The Xeon 676X uses eight-channel DDR5, rated at 409.6 GB/s. This 40% bandwidth advantage for AMD is a major factor in memory-bound workloads, such as the random string sorting test.

Both processors support DDR5 with ECC and offer the same 128 PCIe Gen 5 lanes. TDP is nearly identical at 280W for AMD and 275W for Intel. The Xeon 676X has an unlocked multiplier, meaning it can be overclocked, while the EPYC 9355P is locked.

The Verdict

Based strictly on the benchmark data, the AMD EPYC 9355P is the stronger all-around processor. It wins the majority of tests, including all Cinebench versions, and holds a 1.1% lead in average benchmark score. For users running a diverse mix of server workloads—databases, encryption, compression, or general multi-threaded compute—the EPYC 9355P is the clear pick. Its wins are broad and often decisive.

The Intel Xeon 676X is for a specific user. If floating-point math is the dominant workload, the 9.5% lead is not trivial. Similarly, if a particular application is single-threaded and sensitive to boost clocks, the Xeon’s 6.7% PassMark single-thread win could be more relevant than AMD’s Cinebench single-core victory. The unlocked multiplier also offers headroom for those willing to overclock, a feature the AMD part lacks.

The architecture supports these conclusions. AMD’s larger L3 cache, higher memory bandwidth, and higher base clock align with its multi-core and memory-sensitive wins. Intel’s higher boost clock and larger per-core L2 cache align with its floating-point and single-thread strengths.

FAQ

Q: Which processor has a higher average benchmark score?

A: The AMD EPYC 9355P has an average benchmark score of 160,358, while the Intel Xeon 676X scores 158,540, a 1.1% difference in favor of AMD.

Q: What is the largest margin of victory in any single test?

A: The AMD EPYC 9355P wins the PassMark physics test by 63.2%, scoring 13,515 compared to the Intel Xeon 676X’s 8,281.

Q: In which tests does the Intel Xeon 676X outperform the AMD EPYC 9355P?

A: The Xeon 676X wins three tests: PassMark floating-point math (283,570 vs 256,635), PassMark single-thread (4,015 vs 3,747), and PassMark singlethread (4,015 vs 3,747).

Q: How do the clock speeds compare between the two processors?

A: The AMD EPYC 9355P has a base clock of 3.55 GHz and a boost clock of 4.40 GHz. The Intel Xeon 676X has a lower base clock of 2.80 GHz but a higher boost clock of 4.90 GHz.

Q: What are the memory bandwidth specifications for each chip?

A: The AMD EPYC 9355P supports twelve-channel DDR5 with a bandwidth of 576.0 GB/s. The Intel Xeon 676X supports eight-channel DDR5 with a bandwidth of 409.6 GB/s.

Q: Do both processors have the same number of cores and threads?

A: Yes, both the AMD EPYC 9355P and the Intel Xeon 676X have 32 cores and 64 threads.

Specification Differences

| Specification | AMD EPYC 9355P | Intel Xeon 676X |

|---|---|---|

| Base Clock | 3.55 GHz | 2.80 GHz |

| Boost Clock | 4.40 GHz | 4.90 GHz |

| TDP | 280 W | 275 W |

| Socket | AMD Socket SP5 | Intel Socket 4710 |

| Architecture | Zen 5 | Granite Rapids |

| Codename | Turin | Granite Rapids |

| Process Node | 4 nm | 5 nm |

| Foundry | TSMC | Intel |

| Die Size | 8x 70.6 mm² | 2x 598 mm² |

| L1 Cache | 80 KB (per core) | 112 KB (per core) |

| L2 Cache | 1 MB (per core) | 2 MB (per core) |

| L3 Cache | 256 MB (shared) | 144 MB (shared) |

| Memory Bus | Twelve-channel | Eight-channel |

| Memory Bandwidth | 576.0 GB/s | 409.6 GB/s |

| Launch MSRP | $2998 | $2499 |

| Multiplier Unlocked | No | Yes |