AMD EPYC 9634 vs Intel Xeon 6781P Comparison

The Verdict

The Intel Xeon 6781P is the clear benchmark winner in this comparison, taking 12 of 14 head-to-head tests against the AMD EPYC 9634. Its average benchmark score of 315,524 places it 1.2% ahead of the AMD EPYC 9575F and 1.6% ahead of the AMD EPYC 9734, while the EPYC 9634's average score of 244,274 trails the Intel Xeon 6747P by 2.5% and the Intel Xeon 6980P by 2.9%. The data shows a straightforward choice: the Xeon 6781P dominates the EPYC 9634 in nearly every measured workload category, with the sole exceptions being integer math and data encryption.

For buyers prioritizing raw multi-threaded throughput, the Xeon 6781P is the default selection. It wins Cinebench R15, R20, and R23 multicore by a consistent 9.3% margin, and it extends that advantage to PassMark multithread with the same 9.3% delta. The Xeon also delivers decisive wins in extended instructions (44.7% ahead), prime number finding (43.5% ahead), and floating-point math (43.4% ahead), making it the stronger option for scientific computing, simulation, and instruction-heavy enterprise workloads. The EPYC 9634, by contrast, is the pick only when integer-heavy processing or encryption throughput is the critical constraint, as it leads by 19.4% in integer math and by 21.3% in data encryption.

The EPYC 9634 does offer a lower TDP of 290 watts versus the Xeon's 350 watts, and it provides a twelve-channel memory bus with 460.8 GB/s bandwidth versus the Xeon's eight-channel, 409.6 GB/s configuration. However, the benchmark evidence shows that these architectural advantages do not translate into overall performance superiority. For most server and workstation deployments where compute performance is the deciding factor, the Xeon 6781P is the stronger candidate.

Architecture Differences

The two processors represent fundamentally different design philosophies. The Intel Xeon 6781P uses the Granite Rapids architecture on Intel's 5 nm process, built on a dual-die layout with each die measuring 598 mm². The AMD EPYC 9634 uses the Zen 4 architecture (codename Genoa) on TSMC's 5 nm process, employing twelve chiplets, each at 72 mm², with a total transistor count of 78,840 million. The Xeon's monolithic dual-die approach contrasts sharply with AMD's chiplet strategy.

Core and thread counts differ slightly: the Xeon provides 80 cores and 160 threads, while the EPYC provides 84 cores and 168 threads. The EPYC has more cores, yet the Xeon still wins most benchmarks. Cache hierarchies also diverge: the Xeon allocates 112 KB of L1 per core and 2 MB of L2 per core, with 336 MB of shared L3, while the EPYC uses 64 KB L1 per core, 1 MB L2 per core, and 384 MB of shared L3. The EPYC's larger L3 cache does not compensate for the Xeon's performance edge in the recorded tests.

Clock speeds are close, with the Xeon boosting to 3.80 GHz from a 2.00 GHz base, and the EPYC boosting to 3.70 GHz from a 2.25 GHz base. The EPYC's higher base clock and lower TDP (290 watts versus 350 watts) indicate better power efficiency per core, but the Xeon's boost clock advantage of 0.10 GHz, combined with its architecture, yields superior results in the majority of tests. Both processors support DDR5 memory with ECC, but the EPYC's twelve-channel memory bus provides 460.8 GB/s versus the Xeon's eight-channel 409.6 GB/s. PCIe connectivity is similar: Gen 5 with 136 lanes on the Xeon and 128 lanes on the EPYC, both CPU-only.

Head-to-Head Benchmarks

The Xeon 6781P wins the Cinebench multicore suite by a uniform 9.3% margin across R15 (10,105 versus 9,248), R20 (42,106 versus 38,535), and R23 (100,254 versus 91,752). These are the definitive multi-threaded throughput tests, and the consistency of the delta indicates a structural performance advantage rather than a workload-specific artifact. PassMark multithread confirms the trend: 117,946 versus 107,944, again a 9.3% difference.

The Xeon's most dramatic wins come in compute-heavy PassMark subtests. Extended instructions score 199,048 versus 137,543, a 44.7% lead. Prime number finding shows 1,687 versus 1,176, a 43.5% advantage. Floating-point math reaches 507,406 versus 353,784, a 43.4% lead. Physics simulation follows at 17,753 versus 12,291, a 44.4% margin. These results indicate that the Xeon's execution engine is substantially more capable for arithmetic and scientific workloads.

The EPYC 9634 secures its two wins in distinctly different areas. Data encryption scores 151,943 versus 119,623, giving the EPYC a 21.3% lead. Integer math scores 725,356 versus 584,834, a 19.4% advantage. These are significant margins, and they suggest the EPYC's architecture handles integer-heavy and cryptographic operations more efficiently. However, these two wins do not offset the Xeon's dominance elsewhere.

The Xeon also wins the remaining tests by smaller margins. Data compression comes in at 2,441,690 versus 2,236,412, a 9.2% lead. Random string sorting shows 268,573 versus 261,134, a 2.8% edge. Single-thread performance is 3,152 versus 2,924, a 7.8% advantage. These results show that the Xeon is not only faster in multi-threaded scenarios but also holds a single-thread edge, which is notable given the EPYC's higher base clock.

FAQ

Q: Which processor has more cores?

A: The AMD EPYC 9634 has 84 cores and 168 threads, while the Intel Xeon 6781P has 80 cores and 160 threads. Despite having fewer cores, the Xeon wins 12 of 14 head-to-head benchmarks.

Q: What is the biggest performance gap between the two?

A: The largest margin is in PassMark extended instructions, where the Xeon 6781P scores 199,048 versus the EPYC 9634's 137,543, a 44.7% difference. The EPYC's largest win is in data encryption, leading by 21.3%.

Q: How do their memory subsystems compare?

A: The EPYC 9634 uses a twelve-channel memory bus with 460.8 GB/s bandwidth, while the Xeon 6781P uses an eight-channel bus with 409.6 GB/s bandwidth. The EPYC's memory bandwidth advantage does not translate into benchmark wins in the recorded data.

Q: Which processor is better for single-threaded workloads?

A: The Xeon 6781P is better, scoring 3,152 in PassMark single-thread versus the EPYC's 2,924, a 7.8% advantage. The Xeon also has a higher boost clock at 3.80 GHz versus 3.70 GHz.

Q: What is the average benchmark score difference?

A: The Xeon 6781P has an average benchmark score of 315,524, while the EPYC 9634 averages 244,274. The Xeon's nearest rival, the AMD EPYC 9575F, scores 311,774, which is 1.2% lower.

Q: Do both processors support ECC memory?

A: Yes, both the Intel Xeon 6781P and the AMD EPYC 9634 support ECC memory, and both use DDR5.

Where Each One Wins

The Xeon 6781P is the winner for multi-threaded rendering and content creation workloads. Its Cinebench R15, R20, and R23 multicore scores each beat the EPYC by 9.3%, making it the stronger choice for 3D rendering, video encoding, and any task that scales across many cores. The 44.7% lead in extended instructions and the 43.4% lead in floating-point math further solidify its position for scientific simulation, financial modeling, and engineering analysis. The 43.5% advantage in prime number finding and the 44.4% lead in physics simulation make it the clear pick for computational research and physics-based applications.

The Xeon also wins in data compression (9.2% ahead), random string sorting (2.8% ahead), and single-thread performance (7.8% ahead). These wins cover general server tasks, database operations, and everyday compute duties. For any workload that does not fall into the two categories below, the Xeon 6781P is the safer choice based on the recorded data.

The EPYC 9634 wins specifically in data encryption, scoring 151,943 versus 119,623, a 21.3% lead. This makes it the better option for cryptographic operations, secure communications, and workloads that rely heavily on encryption and decryption throughput. Its second win is in integer math, 725,356 versus 584,834, a 19.4% advantage. This suggests suitability for integer-heavy calculations, such as certain database indexing, financial integer arithmetic, or general-purpose integer processing. For these two specific areas, the EPYC 9634 is the superior processor.

Specification Differences

The two processors differ in several key specifications. The Intel Xeon 6781P uses the Granite Rapids architecture with a codename of Granite Rapids, while the AMD EPYC 9634 uses Zen 4 with the codename Genoa. Both use a 5 nm process node, but the Xeon is fabricated by Intel and the EPYC by TSMC. The Xeon has a dual-die design with each die at 598 mm², while the EPYC uses twelve chiplets, each at 72 mm², with a total of 78,840 million transistors.

Core counts differ: 80 cores and 160 threads for the Xeon versus 84 cores and 168 threads for the EPYC. Base clocks are 2.00 GHz for the Xeon and 2.25 GHz for the EPYC, while boost clocks are 3.80 GHz and 3.70 GHz respectively. TDP is 350 watts for the Xeon and 290 watts for the EPYC. The Xeon uses Intel Socket 4710, while the EPYC uses AMD Socket SP5. Cache configurations differ, with the Xeon providing 112 KB L1 and 2 MB L2 per core plus 336 MB shared L3, versus the EPYC's 64 KB L1 and 1 MB L2 per core plus 384 MB shared L3.

Memory support is DDR5 for both, but the Xeon uses an eight-channel bus with 409.6 GB/s bandwidth, while the EPYC uses a twelve-channel bus with 460.8 GB/s. Both support ECC memory. PCIe is Gen 5 on both, with 136 lanes on the Xeon and 128 lanes on the EPYC, both CPU-only. The Xeon has no integrated graphics, and the EPYC's integrated graphics field is not specified. Release dates differ: the Xeon launched on 2025-02-23, while the EPYC launched on 2022-11-09. The launch MSRP for the Xeon is $8960, and for the EPYC it is $10304.