AMD EPYC 7451 vs Intel Core i9-7940X Comparison

The Intel Core i9-7940X and AMD EPYC 7451 represent two divergent approaches to high-core-count computing from 2017. The data shows a clear, consistent pattern across all benchmark tests, with the Intel part taking a narrow but uniform lead in every single workload. The i9-7940X wins all six head-to-head comparisons, yet the margins are remarkably tight, ranging from 4.8% to 5.2%. This places both processors at the 61st percentile among all CPUs, indicating they occupy a similar performance tier despite their architectural differences.

Head-to-Head Benchmarks

The most decisive victory for the Intel Core i9-7940X comes in the single-core Cinebench R15 test, where it scores 305 against the EPYC 7451's 290, a 5.2% advantage. This is the largest delta in the entire comparison, reflecting the i9-7940X's substantially higher boost clock of 4.40 GHz versus the EPYC 7451's 3.20 GHz. The single-core advantage persists across every generation of the Cinebench suite: R20 shows 1271 versus 1212 (4.9%), and R23 shows 3027 versus 2887 (4.8%). These consistent margins indicate a fundamental clock-speed advantage rather than a workload-specific quirk.

In multi-core workloads, the i9-7940X also prevails, though the EPYC 7451 fields 24 cores and 48 threads against the Intel's 14 cores and 28 threads. The Cinebench R15 multi-core result gives the Intel part 2161 against 2061, a 4.9% lead. This pattern repeats exactly in R20 (9006 versus 8589, 4.9%) and R23 (21444 versus 20450, 4.9%). The fact that a 14-core processor consistently beats a 24-core part in heavily threaded rendering benchmarks is striking. It suggests that the EPYC 7451's lower per-core throughput—due to its 2.30 GHz base clock and Zen architecture—cannot compensate for its raw core-count advantage in these tests.

The Geekbench results reinforce the overall picture, though they are only listed for the Intel part. The i9-7940X scores 10516 multi-core and 1445 single-core, contributing to its average benchmark score of 6147. The EPYC 7451's average sits at 5915, which places it just behind the Intel product. Notably, the i9-7940X's nearest rival is the AMD EPYC 7501, with an average score of 6128 and a delta of just 0.3%, while the EPYC 7451's closest competitor is the Intel Core i9-9920X at 5917 with a 0% delta. This cross-matching of rivals shows how closely these two processors track each other in aggregate performance.

The Verdict

The data is unambiguous: the Intel Core i9-7940X wins every benchmark in this comparison. With six wins out of six head-to-head tests, the verdict favors Intel for anyone prioritizing raw application performance. The margins are modest but consistent, hovering near 5% across both single-core and multi-core workloads. For users who run Cinebench-style rendering tasks, the i9-7940X delivers roughly 5% more throughput than the EPYC 7451, which translates to meaningful time savings in long render jobs.

However, the EPYC 7451 is not without its strategic advantages, even if they do not appear in these specific benchmarks. The AMD part offers 24 cores and 48 threads, which is 10 more cores and 20 more threads than the Intel product. In workloads not captured by these tests—particularly highly parallel server tasks that scale linearly with core count—the EPYC 7451's additional resources could theoretically close the gap or even reverse it. The benchmark data shows the Intel part winning in Cinebench and Geekbench, but the EPYC's core-count headroom is a real asset for certain server-side applications.

The production status also matters. The i9-7940X is listed as end-of-life, while the EPYC 7451 remains active. For long-term procurement, the AMD processor has a clear lifecycle advantage. The EPYC 7451 also supports ECC memory, a feature the Intel part lacks, which is critical for data integrity in server environments. The Intel part does have a launch MSRP of $1399, but the EPYC 7451 has no listed launch price, making direct cost comparison impossible from the available data.

Where Each One Wins

The Intel Core i9-7940X wins in every benchmark category in this dataset, but the nature of those wins matters for use-case analysis. In single-core workloads, the Intel part's 4.40 GHz boost clock gives it a 4.8% to 5.2% edge. This makes it the better choice for lightly threaded applications, legacy software that relies on single-thread performance, and tasks like spreadsheet calculations or scripting where one core does most of the work. The Geekbench single-core score of 1445 reinforces this, though no EPYC 7451 equivalent is listed for direct comparison.

In multi-core workloads, the Intel part wins by 4.9% across all three Cinebench versions. This is counterintuitive given the EPYC 7451's 24 cores versus 14, but the benchmark results are clear. For rendering, video encoding, and other heavily threaded creative workloads, the i9-7940X is the faster processor in this comparison. The 19.25 MB of shared L3 cache on the Intel part, combined with its higher clocks, appears to provide better per-thread efficiency in these tests.

The AMD EPYC 7451 wins in areas that are not benchmarked here but are evident from the specification sheet. Its 64 MB of shared L3 cache is more than three times the Intel part's 19.25 MB, which could benefit workloads with large working sets that fit in cache. Its eight-channel memory bus delivers 170.6 GB/s of bandwidth, exactly double the Intel's 85.3 GB/s, making it superior for memory-bandwidth-bound operations like database queries or scientific simulations. The EPYC also supports ECC memory, which is non-negotiable for many server deployments. For users building a server with high core counts, dense memory configurations, and error correction requirements, the EPYC 7451 is the appropriate choice despite losing the performance benchmarks.

FAQ

Q: Which processor has a higher single-core score in Cinebench R23?

A: The Intel Core i9-7940X scores 3027 in Cinebench R23 single-core, while the AMD EPYC 7451 scores 2887, giving Intel a 4.8% advantage.

Q: Does the AMD EPYC 7451 offer more cores than the Intel Core i9-7940X?

A: Yes, the EPYC 7451 has 24 cores and 48 threads, while the i9-7940X has 14 cores and 28 threads.

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

A: The AMD EPYC 7451 provides 170.6 GB/s of memory bandwidth via its eight-channel memory bus, exactly double the Intel Core i9-7940X's 85.3 GB/s from its quad-channel bus.

Q: Which processor supports ECC memory?

A: The AMD EPYC 7451 supports ECC memory, while the Intel Core i9-7940X does not.

Q: How do these processors compare in average benchmark score?

A: The Intel Core i9-7940X has an average benchmark score of 6147, while the AMD EPYC 7451 has an average of 5915. The Intel part's nearest rival is the AMD EPYC 7501 at 6128, and the EPYC 7451's nearest rival is the Intel Core i9-9920X at 5917.

Q: Are both processors unlocked for overclocking?

A: Yes, both the Intel Core i9-7940X and the AMD EPYC 7451 have an unlocked multiplier.

Architecture Differences

The two processors are built on fundamentally different architectures. The Intel Core i9-7940X uses the Skylake-X architecture, specifically the Skylake codename, fabricated on Intel's 14 nm process with a die size of 484 mm². It belongs to the Core i9 X-Series 7th Generation and uses the Intel Socket 2066. The AMD EPYC 7451 is based on the Zen architecture with the Naples codename, also on a 14 nm process but fabricated by GlobalFoundries, with a significantly smaller die size of 213 mm² and 4,800 million transistors. It uses AMD Socket SP3 and belongs to the EPYC 7001 series.

The core and cache configurations differ substantially. The Intel part provides 64 KB of L1 cache per core and 1 MB of L2 cache per core, with 19.25 MB of shared L3 cache. The AMD part offers 96 KB of L1 cache per core but only 512 KB of L2 cache per core, yet it has 64 MB of shared L3 cache. This gives AMD a massive L3 advantage that could benefit certain cache-sensitive workloads, though the benchmark data does not show this translating into wins on the tested applications.

Memory architecture diverges sharply. The Intel i9-7940X uses a quad-channel DDR4 memory bus delivering 85.3 GB/s, while the AMD EPYC 7451 uses an eight-channel DDR4 bus delivering 170.6 GB/s. The EPYC also supports ECC memory, which the Intel part does not. For PCIe, the Intel processor provides Gen 3 with 44 lanes from the CPU, while the AMD part lists simply Gen 3 without a lane count in the available data.

Clock speeds and power characteristics also differ. The Intel part has a base clock of 3.10 GHz and a boost clock of 4.40 GHz, with a TDP of 165 watts. The AMD part has a base clock of 2.30 GHz and a boost clock of 3.20 GHz, with a higher TDP of 180 watts. The Intel part's higher clocks explain its benchmark victories, while the AMD part's lower clocks but higher core count and cache capacity define its server-oriented design. The Intel part launched on 2017-08-31 with a launch MSRP of $1399, while the AMD part launched earlier on 2017-06-28 with no listed launch MSRP.