AMD EPYC 7643P vs Intel Xeon 674X Comparison

The AMD EPYC 7643P and Intel Xeon 674X are both 98th-percentile server processors, but they achieve that status through radically different designs. The AMD part, a 48-core Zen 3 Milan chip, and the Intel part, a 28-core Granite Rapids chip, split the benchmark suite almost down the middle in terms of workload type, with Intel winning 11 of 16 head-to-head tests and AMD winning the remaining 5. The data reveals that the Xeon 674X dominates in raw compute throughput and single-thread speed, while the EPYC 7643P counters with significant leads in memory-sensitive and encryption-heavy tasks, making the choice between them a matter of workload profile rather than overall superiority.

Head-to-Head Benchmarks

The most striking result in the comparison is the single-thread performance gap. In PassMark's single-thread test, the Intel Xeon 674X scores 3933 against the AMD EPYC 7643P's 2655, a 32.5% advantage. This pattern repeats across all Cinebench single-core tests, where Intel leads by 8.2% to 8.3% in R15, R20, and R23. The Xeon's 4.90 GHz boost clock, compared to the EPYC's 3.60 GHz, is the primary driver of this consistent edge.

The multi-core Cinebench results tell a similar story in favor of Intel, though by a smaller margin. In Cinebench R23 multicore, the Xeon 674X scores 71566 versus 65710 for the EPYC, an 8.2% lead. This is notable because the EPYC 7643P has 48 cores and 96 threads, while the Xeon has only 28 cores and 56 threads. The fact that Intel can overcome a 20-core deficit in a heavily multithreaded workload highlights the architectural efficiency of the Granite Rapids cores. The same 8.2% margin appears in Cinebench R15 and R20 multicore tests, with scores of 7213 vs 6623 and 30057 vs 27598 respectively.

The PassMark multithread test also goes to Intel, with a score of 84196 versus 77307, another 8.2% margin. This consistency across different rendering engines suggests the Xeon's advantage is not workload-specific but rather a fundamental throughput advantage.

However, the EPYC 7643P fights back decisively in several specialized workloads. The largest win for AMD is in data encryption, where it scores 95606 against the Xeon's 61195, a massive 56.2% advantage. This is likely attributable to the EPYC's Zen 3 architecture having dedicated encryption instructions that scale better across its 48 cores. The integer math test also favors AMD strongly, with a score of 390775 versus 308968, a 26.5% lead.

Memory-intensive workloads show a similar pattern. The EPYC 7643P wins PassMark data compression by 7.3% (1326051 vs 1236272) and random string sorting by 25.7% (160274 vs 127529). The physics test is closer, with AMD ahead by 5.5% (8002 vs 7586). These wins suggest that while the Xeon has higher per-core throughput, the EPYC's larger core count and shared 256 MB L3 cache provide advantages in tasks that benefit from massive parallelism and large working sets.

The extended instructions test is the only other decisive Intel win beyond the Cinebench suite. The Xeon 674X scores 97373 versus 67398 for the EPYC, a 30.8% lead. The find prime numbers test is closer, with Intel ahead by 6.1% (693 vs 651), and floating point math goes to Intel by 11.2% (243877 vs 216592). These results indicate that the Xeon's AVX-512-capable cores have a significant advantage in vectorized arithmetic, while the EPYC's strengths lie in memory bandwidth and cryptographic workloads.

FAQ

Q: Which processor has a higher single-thread score?

A: The Intel Xeon 674X is significantly faster in single-thread workloads. It scores 3933 in PassMark single-thread, which is 32.5% higher than the AMD EPYC 7643P's 2655. The gap is consistent across Cinebench R15, R20, and R23 single-core tests, where Intel leads by approximately 8.2%.

Q: How does the core count difference affect multi-core performance?

A: Despite having 20 fewer cores (28 vs 48) and 40 fewer threads (56 vs 96), the Intel Xeon 674X still wins all Cinebench multicore tests by 8.2%. This indicates that the Granite Rapids cores are substantially more efficient per core than the Zen 3 cores in the EPYC 7643P.

Q: In which workload does the AMD EPYC 7643P have its largest advantage?

A: The largest AMD win is in PassMark data encryption, where it scores 95606 versus 61195 for the Intel Xeon 674X, a 56.2% advantage. This is the single biggest margin in the entire head-to-head comparison.

Q: What is the difference in memory bandwidth between the two processors?

A: The Intel Xeon 674X supports DDR5 memory over an eight-channel bus, providing a theoretical bandwidth of 409.6 GB/s. The AMD EPYC 7643P uses DDR4 over an eight-channel bus, with a theoretical bandwidth of 204.8 GB/s. This gives the Xeon exactly double the memory bandwidth.

Q: Are both processors in the same performance percentile?

A: Yes, both the AMD EPYC 7643P and the Intel Xeon 674X are in the 98th percentile of all CPUs. Their average benchmark scores are very close: 144824 for the EPYC and 143103 for the Xeon, a difference of just 1.2%.

Q: Which processor has a higher boost clock?

A: The Intel Xeon 674X has a boost clock of 4.90 GHz, which is significantly higher than the AMD EPYC 7643P's 3.60 GHz. The base clocks are closer, at 3.00 GHz for Intel and 2.30 GHz for AMD.

Where Each One Wins

The Intel Xeon 674X is the clear choice for workloads that are dominated by single-thread performance and raw compute throughput. Its 32.5% lead in PassMark single-thread performance and 30.8% lead in extended instructions make it ideal for database queries, web serving, and any application that relies on high clock speeds and vectorized arithmetic. The consistent 8.2% advantage across all Cinebench multicore tests also makes it the better option for rendering and simulation tasks that are well-parallelized but not memory-bound. The Xeon's 409.6 GB/s memory bandwidth, double that of the EPYC, further supports high-throughput compute workloads.

The AMD EPYC 7643P is the better choice for workloads that involve heavy data encryption, large integer math operations, and memory-resident data manipulation. Its 56.2% lead in data encryption makes it particularly well-suited for secure communications, VPN gateways, and storage encryption. The 26.5% advantage in integer math and 25.7% lead in random string sorting suggest it excels in data analytics, log processing, and text-heavy workloads. The 7.3% win in data compression also makes it competitive for backup and archival systems. The EPYC's larger core count (48 vs 28) is the likely reason for its success in these parallel, data-intensive tasks.

For mixed workloads, the decision becomes more nuanced. The EPYC 7643P wins the physics test by 5.5%, suggesting an edge in certain simulation workloads. However, the Xeon wins floating point math by 11.2%, indicating better performance in scientific computing. The Xeon's win in find prime numbers (6.1%) is a minor data point but suggests it handles number-crunching loops slightly better.

Specification Differences

The two processors differ significantly in their core and thread counts. The AMD EPYC 7643P has 48 cores and 96 threads, while the Intel Xeon 674X has 28 cores and 56 threads. Clock speeds also differ, with the EPYC running at 2.30 GHz base and 3.60 GHz boost, while the Xeon runs at 3.00 GHz base and 4.90 GHz boost. The thermal design power (TDP) is higher for the Intel part at 270 watts, compared to 225 watts for the AMD part.

Memory support is a major differentiator. The EPYC 7643P uses DDR4 memory with a bandwidth of 204.8 GB/s, while the Xeon 674X uses DDR5 with a bandwidth of 409.6 GB/s. Both use eight-channel memory buses and support ECC. The PCIe interface also differs, with the EPYC offering Gen 4 with 128 lanes and the Xeon offering Gen 5 with 128 lanes.

The sockets are incompatible: the EPYC uses AMD Socket SP3, while the Xeon uses Intel Socket 4710. The EPYC has a launch MSRP of $2722, while the Xeon has a launch MSRP of $2199. The Xeon has an unlocked multiplier, while the EPYC does not. The release dates differ substantially, with the EPYC launching on 2023-09-04 and the Xeon on 2026-02-01.

Architecture Differences

The architectural divide is stark. The AMD EPYC 7643P is built on the Zen 3 architecture, codenamed Milan, using a 7 nm process from TSMC. It has 33,200 million transistors across 8 dies, each measuring 81 mm². The cache hierarchy consists of 64 KB of L1 and 512 KB of L2 per core, with a shared 256 MB L3 cache. This large L3 cache is a defining feature of the Milan design, providing a massive pool of fast memory for all 48 cores.

The Intel Xeon 674X uses the Granite Rapids architecture, built on a 5 nm process at Intel. It has no transistor count listed, but the die size is 2x 598 mm², indicating a dual-die design. The cache hierarchy is quite different: 112 KB of L1 and 2 MB of L2 per core, with a shared 144 MB L3 cache. The per-core L2 cache is 4 times larger than the AMD's, which helps explain the Xeon's strong single-thread performance. However, the total L3 cache is significantly smaller than the EPYC's 256 MB.

The EPYC 7643P belongs to the EPYC 7003 series and uses the Zen 3 microarchitecture, which is a mature design optimized for high core counts. The Xeon 674X is part of the Xeon 600 generation (Granite Rapids-WS) and represents a newer, more power-hungry design with higher clock speeds and lower core counts. The EPYC's 7 nm process from TSMC is older than Intel's 5 nm process, which contributes to the difference in power efficiency and clock speeds. The Xeon's integrated graphics is listed as N/A, meaning it has none, while the EPYC's integrated graphics field is null, indicating it also has no integrated GPU.