AMD EPYC 7642 vs Intel Xeon 6521P Comparison

The AMD EPYC 7642 and Intel Xeon 6521P occupy the same server/workstation segment, but the recorded benchmark data shows two very different performance profiles. The AMD part, a 48-core Zen 2 design, and the Intel part, a 24-core Granite Rapids chip, split wins across the test suite, with Intel taking 12 of the 17 head-to-head comparisons, while AMD wins 5. The Intel Xeon 6521P posts a higher average benchmark score of 105,845, but the AMD EPYC 7642 counters with a much larger average of 124,006. This gap is significant, yet the per-test breakdown is more nuanced than a single average suggests, with each processor dominating distinct workloads.

Head-to-Head Benchmarks

The most decisive Intel advantage appears in single-threaded performance. In the PassMark single-thread test, the Xeon 6521P scores 3,238 against the EPYC 7642’s 2,052, a 36.6% difference. This is the largest delta in the entire comparison. The same pattern holds in Cinebench single-core tests, though the margins are smaller. In Cinebench R15 single-core, the Intel part scores 806 versus 711, an 11.8% lead. That exact 11.8% delta repeats across all three Cinebench single-core and multi-core tests: R15, R20, and R23. For instance, in Cinebench R23 multi-core, the Intel Xeon 6521P scores 56,658, while the EPYC 7642 scores 49,975, again an 11.8% gap. This consistency suggests a per-clock or per-core efficiency advantage for Intel, not just a clock speed effect.

The Intel chip also wins in multi-threaded synthetic loads. In PassMark multithread, the Xeon 6521P scores 66,657 vs 58,795, an 11.8% advantage. PassMark physics shows a similar story: 5,972 for Intel vs 5,098 for AMD, a 14.6% lead. In PassMark find prime numbers, the Intel part scores 560 vs 496, an 11.4% edge. Extended instructions also go to Intel, with a score of 72,820 vs 68,841, a 5.5% margin.

However, the AMD EPYC 7642 counters in several specific workloads, often by large margins. The biggest win for AMD is in PassMark data encryption, where the EPYC scores 86,397 vs 51,221, a 68.7% advantage. That is a dominant result. PassMark integer math also strongly favors AMD, with a score of 305,303 vs 246,263, a 24% lead. In PassMark data compression, the AMD chip scores 1,195,584 vs 967,721, a 23.5% edge. The AMD part also wins in floating-point math, though narrowly: 181,887 vs 178,828, a 1.7% margin. The final AMD win comes in random string sorting, at 114,871 vs 104,517, a 9.9% margin.

Looking at the full picture, the Intel Xeon 6521P is the better performer in CPU-bound tasks like Cinebench and PassMark physics, while the AMD EPYC 7642 excels in data-heavy workloads like encryption and compression. The single-thread gap is the most striking: the Intel part is far ahead, but this does not carry over to every workload. For example, in floating-point math, the AMD chip actually edges ahead, despite the Intel’s higher single-thread score. This indicates that the AMD architecture has strengths in specific instruction patterns that the Intel part cannot match, even with a higher peak clock.

Where Each One Wins

The AMD EPYC 7642 wins in tasks that rely on high-throughput integer processing and memory bandwidth. PassMark data encryption is the standout: a 68.7% lead over the Intel. This suggests that the EPYC 7642’s 8-channel DDR4 memory bus, with a recorded bandwidth of 204.8 GB/s, is very effective for encryption workloads, despite being lower than the Intel’s bandwidth. The integer math win (24% ahead) and compression win (23.5%) point to a server-oriented design that can process many parallel integer operations efficiently. The floating-point win, though small at 1.7%, indicates that the Zen 2 architecture is not inept at FP math, just less optimized than the Intel part.

The Intel Xeon 6521P wins in latency-sensitive, single-threaded workloads and in CPU-heavy multithreaded scenarios. The 36.6% lead in PassMark single-thread is the clearest indicator: this is a chip that will feel faster in interactive tasks or in benchmarks that do not scale perfectly with core count. The Cinebench R23 multi-core win by 11.8% is also notable, because the AMD has twice the cores (48 vs 24). This means the Intel chip is extracting more performance per core, likely due to a higher boost clock (4.10 GHz vs 3.40 GHz) and a more advanced architecture. The PassMark physics win (26.4%) and prime number finding (11.4%) are further signs of Intel’s strength in calculations that depend on high clock rates and low latency.

For a database or a benchmark engineer, the split is clear: use the AMD EPYC 7642 for encryption, compression, and integer-heavy analytics, and use the Intel Xeon 6521P for single-threaded applications, physics simulations, and Cinebench-like rendering tasks where the Intel’s per-core efficiency pays off. The data does not show any middle ground; these are two specialized tools.

Architecture Differences

The two CPUs are built on different process nodes and core architectures. The AMD EPYC 7642 uses the Zen 2 architecture, codenamed Rome, fabricated on a 7 nm process by TSMC. The Intel Xeon 6521P uses the Granite Rapids architecture, also its codename, on a 5 nm process made by Intel. The node difference is small but the transistor count differs: the AMD chip has 3,800 million transistors, while the Intel’s transistor count is not recorded in the database. The die size is also different: AMD’s is 74 mm², while Intel’s is 598 mm². This is a large difference, but it does not directly translate to performance, as the Intel has fewer cores.

The core count is a major difference: the EPYC 7642 has 48 cores and 96 threads, while the Xeon 6521P has 24 cores and 48 threads. Despite having half the cores, the Intel chip still wins in most multithreaded benchmarks, which reflects its higher clock speed (4.10 GHz boost vs 3.40 GHz) and likely a more efficient core design. The base clocks are closer: 2.60 GHz for Intel vs 2.40 GHz for AMD, but the boost difference is large.

Cache hierarchies are also divergent. The AMD EPYC 7642 has a large L3 cache of 256 MB (shared), while the Intel Xeon 6521P has 144 MB (shared). However, the Intel part has a larger L2 cache per core: 2 MB per core vs AMD’s 512 KB per core. The L1 cache is also different: Intel has 112 KB per core, AMD has 96 KB per core. These cache differences likely influence the single-threaded and multithreaded performance in different ways. AMD’s massive L3 (256 MB) helps in workloads that fit in that shared cache, such as data compression. Intel’s larger per-core L2 and L1 might benefit single-threaded performance.

Memory support is another clear difference. The AMD EPYC 7642 supports DDR4 memory, while the Intel Xeon 6521P supports DDR5. Both have an eight-channel memory bus, but the bandwidth is much higher on the Intel: 409.6 GB/s vs 204.8 GB/s. This is exactly a 100% increase in theoretical bandwidth. Yet, the AMD chip still wins in compression and encryption, which are memory-intensive. This indicates that the AMD’s larger L3 cache mitigates the lower memory bandwidth in those workloads.

PCIe support also differs: the AMD uses Gen 4, while the Intel uses Gen 5 with 136 lanes (CPU only). The AMD has no integrated graphics, and the Intel’s graphics is listed as “N/A” as well. Both are server processors, so this is expected. The AMD socket is SP3, and the Intel is Socket 4710.

The release dates are far apart: the AMD EPYC 7642 was released on 2019-08-06, and the Intel Xeon 6521P on 2025-02-23. This is a generational gap. The AMD is from the EPYC 7002 series (Zen 2 Rome), while the Intel is from the Xeon 6 (Granite Rapids-SP) family. The process node difference (7 nm vs 5 nm) reflects the newer Intel design.

FAQ

Q: Which CPU has more cores and threads?

A: The AMD EPYC 7642 has 48 cores and 96 threads, while the Intel Xeon 6521P has 24 cores and 48 threads. The AMD has double the core and thread count.

Q: Why does the Intel Xeon 6521P win in most benchmarks despite having fewer cores?

A: The Intel part has a higher boost clock (4.10 GHz vs 3.40 GHz) and a newer architecture (Granite Rapids on 5 nm vs Zen 2 on 7 nm). The data shows a consistent 11.8% lead in Cinebench tests, which is likely due to better per-core performance.

Q: Is the AMD EPYC 7642 better than the Intel Xeon 6521P in any workload?

A: Yes, the AMD wins in 5 benchmarks: data compression (23.5% lead), data encryption (68.7% lead), integer math (24% lead), floating-point math (1.7% lead), and random string sorting (9.9% lead). These are data and integer-heavy workloads.

Q: What is the difference in memory bandwidth?

A: The Intel Xeon 6521P has a recorded memory bandwidth of 409.6 GB/s with DDR5, while the AMD EPYC 7642 has 204.8 GB/s with DDR4. The Intel has double the theoretical memory bandwidth.

Q: Which CPU has the higher average benchmark score?

A: The AMD EPYC 7642 has an average benchmark score of 124,006, while the Intel Xeon 6521P has an average of 105,845. This is a significant difference, despite the Intel winning more individual tests.

Q: Do both CPUs support ECC memory?

A: Yes, both the AMD EPYC 7642 and the Intel Xeon 6521P have ECC memory support.

Specification Differences

| Specification | AMD EPYC 7642 | Intel Xeon 6521P |

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

| Cores | 48 | 24 |

| Threads | 96 | 48 |

| Base Clock | 2.40 GHz | 2.60 GHz |

| Boost Clock | 3.40 GHz | 4.10 GHz |

| L1 Cache | 96 KB (per core) | 112 KB (per core) |

| L2 Cache | 512 KB (per core) | 2 MB (per core) |

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

| Process Node | 7 nm (TSMC) | 5 nm (Intel) |

| Transistors | 3,800 million | Not recorded |

| Die Size | 74 mm² | 598 mm² |

| Memory Support | DDR4 | DDR5 |

| Memory Bandwidth | 204.8 GB/s | 409.6 GB/s |

| PCIe | Gen 4 | Gen 5, 136 Lanes (CPU only) |

| Socket | AMD Socket SP3 | Intel Socket 4710 |

| Release Date | 2019-08-06 | 2025-02-23 |

| Launch MSRP | Not recorded | $1250 |

The launch MSRP for the Intel Xeon 6521P is $1250. The AMD EPYC 7642 has no recorded launch MSRP in the database. The Intel has a higher base and boost clock, a larger per-core L2 cache, and double the memory bandwidth. The AMD has more cores, a larger L3 cache, and a 7 nm process node. The Intel is a newer design, released in 2025, while the AMD is from 2019. The benchmark data shows that the Intel’s newer architecture and higher clocks make it the winner in most tests, but the AMD’s core count and large L3 cache keep it competitive in specific workloads. The AMD also has a much higher average benchmark score (124,006 vs 105,845), which is likely due to the heavy weighting of the integer and encryption scores in the average calculation. The Intel’s win count is higher (12 vs 5), but the AMD’s wins are larger in magnitude, especially the encryption test. The choice between these two processors depends entirely on the workload. For a database that does heavy compression and encryption, the AMD would be the better option. For a general-purpose server that needs to run single-threaded applications or Cinebench-like workloads, the Intel is superior. The recorded data does not indicate a clear overall winner, only a clear division of labor.