AMD EPYC 9745 vs Intel Xeon 6781P Comparison

Where Each One Wins

The benchmark split between the AMD EPYC 9745 and the Intel Xeon 6781P is remarkably stark, with 10 wins going to the AMD part and 4 to the Intel part. The pattern is clear: the EPYC 9745 dominates in throughput-heavy, multi-threaded, and data-parallel workloads, while the Xeon 6781P claims victory in single-threaded and latency-sensitive tasks. This is not a close contest across the board; it is a tale of two very different optimization strategies.

The AMD EPYC 9745 wins every Cinebench multicore test (R15, R20, R23), each by an identical 10.8% margin. It also sweeps the Passmark suite's data compression, encryption, extended instructions, floating point math, integer math, multithread, and random string sorting tests. The largest wins are in integer math (109.3% ahead) and data encryption (91.8% ahead), which are enormous deltas suggesting a fundamental architectural advantage in raw compute throughput. Data compression shows a 60.9% lead, and floating point math is 50% higher. These are not marginal victories; they are category-defining gaps.

The Intel Xeon 6781P, by contrast, wins only four tests: Passmark find prime numbers (42% ahead), Passmark physics (3.6% ahead), and both Passmark single-thread tests (11% ahead). The prime number test is a notable outlier, where Intel's higher boost clock and per-core efficiency shine through. The physics test, while a win, is narrow. The single-thread wins are consistent and meaningful, but they represent a minority of the workload profile.

For server deployments, the implication is straightforward: if the workload scales across many cores and involves heavy data manipulation, the EPYC 9745 is the clear choice. If the application is latency-bound, lightly threaded, or relies on prime-number computation, the Xeon 6781P offers a measurable edge. The EPYC's 128 cores versus the Xeon's 80 cores explain much of the multicore dominance, but the single-thread deficit of the EPYC (2.80 GHz base, 3.70 GHz boost) versus the Xeon (2.00 GHz base, 3.80 GHz boost) explains the reverse.

FAQ

Q: Which processor is faster in multi-core rendering?

A: The AMD EPYC 9745 wins all three Cinebench multicore tests by exactly 10.8%. In Cinebench R23, it scores 111,093 versus the Intel Xeon 6781P's 100,254.

Q: Does the Intel Xeon 6781P have any performance advantage at all?

A: Yes, four tests favor Intel. The most significant is Passmark find prime numbers, where Intel wins by 42%. It also wins Passmark physics by 3.6% and both Passmark single-thread tests by 11%.

Q: How large is the gap in data encryption performance?

A: The EPYC 9745 scores 229,447 in Passmark data encryption versus 119,623 for the Xeon 6781P, a 91.8% advantage for AMD. This is the largest single-test delta in the head-to-head comparison.

Q: What about integer math performance?

A: The EPYC 9745 more than doubles the Xeon's score in Passmark integer math: 1,224,315 versus 584,834, a 109.3% lead. This is the most extreme difference recorded between the two.

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

A: The Intel Xeon 6781P scores 3,152 in Passmark single-thread, which is 11% higher than the EPYC 9745's 2,806. This aligns with Intel's higher boost clock of 3.80 GHz compared to 3.70 GHz for AMD.

Q: How do the average benchmark scores compare?

A: The EPYC 9745 has an average benchmark score of 425,973, which places it in the 100th percentile of all CPUs. The Xeon 6781P averages 315,524, placing it in the 99th percentile. The EPYC's nearest rival, the Threadripper PRO 9995WX, sits 3.4% lower, while the Xeon's closest competitor, the EPYC 9575F, is 1.2% behind.

Head-to-Head Benchmarks

The most decisive victories for the AMD EPYC 9745 occur in Passmark integer math and data encryption. In integer math, the EPYC scores 1,224,315 against the Xeon's 584,834, a 109.3% advantage. This means the AMD part is performing more than double the integer operations per second. The encryption test shows a 91.8% gap: 229,447 versus 119,623. These two tests alone demonstrate a fundamental difference in compute density, likely due to the EPYC's 128 cores versus 80, and its 256 threads versus 160.

Data compression is another blowout: the EPYC scores 3,929,890 versus 2,441,690, a 60.9% delta. Random string sorting follows at 74.6% (468,975 versus 268,573). Floating point math shows a 50% lead (761,219 versus 507,406). Extended instructions are 40.9% higher for AMD (280,477 versus 199,048). All three Cinebench multicore tests show a consistent 10.8% delta, with R15 at 11,198 versus 10,105, R20 at 46,659 versus 42,106, and R23 at 111,093 versus 100,254. The multithread Passmark test also lands at 10.8% (130,698 versus 117,946).

The Intel Xeon 6781P's wins are narrower in percentage terms except for the prime number test. Passmark find prime numbers shows Intel at 1,687 versus AMD's 979, a 42% advantage. This is a workload that rewards high per-core frequency and perhaps a different branch predictor behavior. The physics test is close: 17,753 versus 17,122, a 3.6% edge for Intel. Single-thread performance is 3,152 versus 2,806, an 11% lead for Intel, consistent across both Passmark single-thread fields.

What stands out is the asymmetry: AMD wins by massive margins in data-heavy workloads, while Intel wins by smaller margins in latency-sensitive ones. The only exception is the prime number test, where Intel's 42% lead is substantial. Overall, the EPYC 9745 wins 10 of 14 head-to-head tests, and its average delta across all wins is far larger than Intel's average delta across its four wins.

Specification Differences

The core disparity is the defining difference: the AMD EPYC 9745 has 128 cores and 256 threads, while the Intel Xeon 6781P has 80 cores and 160 threads. This is a 60% difference in core count, which directly explains the multicore benchmark results. Clock speeds differ in an interesting way: the EPYC has a higher base clock (2.40 GHz versus 2.00 GHz) but a lower boost clock (3.70 GHz versus 3.80 GHz). The EPYC also carries a higher TDP of 400 watts versus 350 for the Xeon.

Memory architecture differs significantly. The EPYC uses a twelve-channel memory bus with a bandwidth of 576.0 GB/s, while the Xeon uses an eight-channel bus at 409.6 GB/s. This 40% bandwidth advantage for AMD is critical for the data compression and encryption workloads where it won by 60% to 92%. Both support DDR5 and ECC memory. PCIe lanes are close: the EPYC offers 128 Gen 5 lanes (CPU only), while the Xeon offers 136 Gen 5 lanes (CPU only), a slight edge for Intel.

Cache hierarchies diverge substantially. The EPYC has 80 KB of L1 per core and 1 MB of L2 per core, with 256 MB of shared L3. The Xeon has 112 KB of L1 per core and 2 MB of L2 per core, with a larger 336 MB of shared L3. The Xeon's larger per-core caches may explain its single-thread wins, while the EPYC's larger total thread count compensates in aggregate.

Sockets are incompatible: AMD Socket SP5 versus Intel Socket 4710. Process nodes differ, with the EPYC on TSMC's 3 nm process and the Xeon on Intel's 5 nm process. The Xeon's die size is listed as 2x 598 mm², a dual-die design. Launch MSRP for the EPYC 9745 is $12,141, and for the Xeon 6781P it is $8,960. Both are active production parts, launched on 2024-10-09 and 2025-02-23 respectively, and both lack an unlocked multiplier.

Architecture Differences

The AMD EPYC 9745 is based on the Zen 5 architecture, codenamed Turin, part of the EPYC 9005 series. It uses a 3 nm process from TSMC. The Intel Xeon 6781P uses the Granite Rapids architecture, part of the Xeon 6 family (Granite Rapids-SP), on a 5 nm process from Intel. These are fundamentally different design philosophies: AMD is pushing for maximum core density with a high thread count, while Intel is prioritizing per-core features and larger caches.

The EPYC's cache layout is optimized for its dense core count: 80 KB L1 and 1 MB L2 per core, with a shared 256 MB L3. The Xeon's per-core caches are larger (112 KB L1, 2 MB L2), and its shared L3 is 336 MB. The Xeon also has a dual-die design (2x 598 mm²), which suggests a chiplet-based approach with two compute dies. The EPYC does not report a die size, but its 3 nm process and 128-core count indicate an extremely dense monolithic or chiplet design from TSMC.

Memory bandwidth is a major architectural differentiator. The EPYC's twelve-channel memory controller delivers 576.0 GB/s, which is 40% higher than the Xeon's eight-channel 409.6 GB/s. This bandwidth headroom is directly visible in the benchmark results: the EPYC wins data compression by 60.9% and random string sorting by 74.6%, both of which are memory-bandwidth-sensitive workloads. The Xeon's higher boost clock (3.80 GHz versus 3.70 GHz) and larger L2 cache are likely the reasons for its 11% single-thread win.

The Xeon also has a slight PCIe advantage at 136 lanes versus 128, but this is unlikely to affect the benchmark results. Both lack integrated graphics and are server/workstation parts. The EPYC's 256 threads versus 160 gives it more simultaneous compute contexts, which is critical for the integer math and encryption tests where it more than doubles the Xeon's scores.

The Verdict

The data points to a clear division of labor. For any workload that scales across many threads, the AMD EPYC 9745 is the definitive choice. Its 128 cores and 256 threads, combined with twelve-channel memory bandwidth, produce decisive victories in integer math (109.3% ahead), encryption (91.8% ahead), and data compression (60.9% ahead). The consistent 10.8% lead across all Cinebench multicore tests reinforces that this is a broad, architectural advantage, not a workload-specific quirk. The EPYC's 100th percentile ranking and average benchmark score of 425,973 versus 315,524 place it in a higher performance tier overall.

The Intel Xeon 6781P is the pick for single-threaded and latency-sensitive tasks. Its 11% lead in Passmark single-thread tests, 42% lead in prime number finding, and marginal 3.6% win in physics point to a processor that excels when per-core frequency and cache matter more than raw thread count. Its 80 cores and 160 threads are still substantial, but the 3.80 GHz boost clock and larger 336 MB L3 cache give it an edge that the EPYC cannot match in these specific scenarios.

The verdict from the database is straightforward: choose the EPYC 9745 for large-scale parallel compute, data processing, and rendering; choose the Xeon 6781P for workloads that are lightly threaded, frequency-bound, or require its specific prime-number and physics performance profile. The EPYC's 10 wins out of 14 tests, with many by massive margins, make it the default recommendation for general server use. The Xeon's four wins, while narrower, carve out a legitimate niche for single-thread-critical applications. Neither part is a universal winner, but the EPYC 9745 is the more broadly dominant processor in this comparison.