AMD EPYC 7643 vs Intel Core i7-8700K Comparison

Head-to-Head Benchmarks

The AMD EPYC 7643 dominates every recorded benchmark in this comparison. Across all six Cinebench tests, the EPYC 7643 wins outright, leaving the Intel Core i7-8700K trailing by a consistent margin of roughly 82%. The single-core results are just as lopsided as the multi-core results, which is a striking outcome for a 48-core server processor against a 6-core desktop chip.

In Cinebench R23 multi-core, the EPYC 7643 scores 64,642 points versus 11,527 for the i7-8700K, a delta of -82.2%. This gap reflects the enormous core count advantage: 48 cores with 96 threads against 6 cores with 12 threads. The single-core R23 result shows the EPYC 7643 at 9,126 points, while the i7-8700K manages 1,627, again a -82.2% delta. The EPYC 7643 does not merely win on parallel throughput; it also holds a commanding lead in lightly threaded workloads.

The pattern repeats in Cinebench R20. The EPYC 7643 posts 27,149 in multi-core, and the i7-8700K scores 4,841. In single-core R20, the EPYC 7643 reaches 3,832, while the i7-8700K sits at 683. Every delta in the head-to-head table is -82.2%, with the exception of R15 single-core at -82.3%. The consistency of these percentages suggests a fixed performance relationship between the two chips across the Cinebench suite, rather than workload-specific variation.

Cinebench R15 follows the same script: 6,515 versus 1,161 in multi-core, and 919 versus 163 in single-core. The i7-8700K records no wins in any benchmark category. The win count stands at 6 for the EPYC 7643 and 0 for the i7-8700K.

It is notably the i7-8700K has additional benchmark data not present in the head-to-head table. The Geekbench multi-core score is 7,140, and single-core is 1,575. Passmark results include multi-thread at 13,576, single-thread at 2,720, integer math at 45,892, and floating point math at 28,538. These numbers are not directly compared here because the EPYC 7643 lacks corresponding entries in the database, but they provide context for the i7-8700K's overall standing. The average benchmark score for the i7-8700K is 19,238, while the EPYC 7643 averages 18,697. Both processors sit at the 73rd percentile among all CPUs, meaning they occupy the same tier in the overall distribution despite the EPYC's absolute dominance in the tested workloads.

The Verdict

The data leaves no ambiguity: the AMD EPYC 7643 is the superior processor in every benchmark where both were measured. The i7-8700K cannot close the gap in any test, not even in single-core performance where desktop chips typically hold an advantage. The EPYC 7643's single-core R23 score of 9,126 is more than five times the i7-8700K's 1,627. This is not a case of a niche server chip winning only on throughput; it wins everywhere.

For a user choosing between these two, the decision hinges on the workload and platform requirements. The EPYC 7643 is a server and workstation part with 48 cores, 96 threads, eight-channel memory, and 128 PCIe Gen 4 lanes. The i7-8700K is a desktop chip with 6 cores, 12 threads, dual-channel memory, and 16 PCIe Gen 3 lanes. The EPYC 7643 costs far more at launch, $4,995 versus $359, but the database does not assess price-to-performance, and this analysis sticks strictly to measured results.

The EPYC 7643 is the clear pick for any workload that scales with cores: rendering, simulation, virtualization, or heavy compilation. The i7-8700K is the only choice if the platform demands a desktop socket, integrated graphics, or a 95 W TDP. The i7-8700K includes UHD Graphics 630, while the EPYC 7643 has no integrated graphics. The i7-8700K also has an unlocked multiplier, enabling overclocking, whereas the EPYC 7643 is locked. These are feature differences, not performance equalizers. On raw benchmark scores, the EPYC 7643 wins every recorded comparison.

Architecture Differences

The two processors come from different eras and design philosophies. The Intel Core i7-8700K uses the Coffee Lake architecture, built on a 14 nm process at Intel's own foundry. It features 6 cores and 12 threads, with a base clock of 3.70 GHz and a boost clock of 4.70 GHz. The die size is 154 mm². Cache layout includes 64 KB of L1 per core, 256 KB of L2 per core, and 12 MB of shared L3.

The AMD EPYC 7643 belongs to the EPYC 7003 series, using the Zen 3 architecture under the codename Milan. It is fabricated on a 7 nm process at TSMC, with 33,200 million transistors spread across 8 dies, each measuring 81 mm². The core count is 48 with 96 threads, running at a base clock of 2.30 GHz and a boost clock of 3.60 GHz. L1 cache is identical at 64 KB per core, but L2 doubles to 512 KB per core, and L3 expands massively to 256 MB shared.

Memory support differs sharply. The i7-8700K uses dual-channel DDR4 with a peak bandwidth of 42.7 GB/s. The EPYC 7643 uses eight-channel DDR4 with 204.8 GB/s, roughly five times the bandwidth. The i7-8700K does not support ECC memory; the EPYC 7643 does. PCIe capabilities also diverge: the i7-8700K offers Gen 3 with 16 lanes from the CPU, while the EPYC 7643 provides Gen 4 with 128 lanes.

The market segments reflect these choices. The i7-8700K is a desktop part, released in 2017, now end-of-life. The EPYC 7643 is a server or workstation processor, released in 2021, still active in production. The EPYC 7643 has no integrated graphics, whereas the i7-8700K includes UHD Graphics 630. The sockets are incompatible: Intel Socket 1151 for the i7-8700K, AMD Socket SP3 for the EPYC 7643.

FAQ

Q: Which processor has more cores?

A: The AMD EPYC 7643 has 48 cores and 96 threads, while the Intel Core i7-8700K has 6 cores and 12 threads.

Q: Does the EPYC 7643 support ECC memory?

A: Yes, the EPYC 7643 supports ECC memory. The i7-8700K does not.

Q: What is the memory bandwidth difference?

A: The EPYC 7643 has eight-channel memory with 204.8 GB/s bandwidth. The i7-8700K has dual-channel memory with 42.7 GB/s.

Q: Which processor has integrated graphics?

A: The i7-8700K includes UHD Graphics 630. The EPYC 7643 has no integrated graphics.

Q: Are both processors unlocked for overclocking?

A: No. The i7-8700K has an unlocked multiplier. The EPYC 7643 is locked.

Q: What is the single-core performance gap in Cinebench R23?

A: The EPYC 7643 scores 9,126 in R23 single-core, while the i7-8700K scores 1,627, a delta of -82.2%.

Where Each One Wins

The EPYC 7643 wins in every benchmark category where both chips were tested. The six head-to-head results cover Cinebench R15, R20, and R23 in both single-core and multi-core modes. The EPYC 7643's multi-core scores are roughly 5.6 times higher than the i7-8700K's, and its single-core scores are also roughly 5.6 times higher. There is no workload category in the recorded data where the i7-8700K takes a win.

For workloads that benefit from high core counts and massive memory bandwidth, the EPYC 7643 is the obvious choice. Its 48 cores, 96 threads, eight-channel memory, and 128 PCIe Gen 4 lanes make it suited for server virtualization, large-scale database operations, scientific computing, and rendering farms. The 256 MB of L3 cache and 204.8 GB/s memory bandwidth support data-heavy tasks that would saturate the i7-8700K's 12 MB L3 and 42.7 GB/s dual-channel interface.

The i7-8700K does have a role, but it is defined by platform constraints rather than benchmark victories. Its 95 W TDP, integrated UHD Graphics 630, and unlocked multiplier make it a viable desktop processor for users who need a compact system without a discrete GPU. The 4.70 GHz boost clock is higher than the EPYC 7643's 3.60 GHz, and the 14 nm Coffee Lake architecture delivers respectable single-thread performance for its era, as shown by its Geekbench single-core score of 1,575 and Passmark single-thread score of 2,720. But in any direct comparison from the database, the EPYC 7643 wins.

Specification Differences

The two processors differ on nearly every recorded specification. The i7-8700K uses 6 cores, the EPYC 7643 uses 48. Thread counts are 12 versus 96. Base clocks are 3.70 GHz versus 2.30 GHz, and boost clocks are 4.70 GHz versus 3.60 GHz. TDP is 95 W versus 225 W. Sockets are Intel Socket 1151 versus AMD Socket SP3. Architecture is Coffee Lake versus Zen 3, with codenames Coffee Lake and Milan respectively. Process nodes are 14 nm versus 7 nm, with foundries Intel versus TSMC.

The EPYC 7643 has 33,200 million transistors and a die size of 8x 81 mm², while the i7-8700K has no transistor count recorded and a die size of 154 mm². L2 cache is 256 KB per core on the i7-8700K versus 512 KB per core on the EPYC 7643. L3 cache is 12 MB shared versus 256 MB shared. Memory bus is dual-channel versus eight-channel. Memory bandwidth is 42.7 GB/s versus 204.8 GB/s. ECC support is false versus true. PCIe is Gen 3 with 16 lanes versus Gen 4 with 128 lanes. Integrated graphics are present on the i7-8700K (UHD Graphics 630) and absent on the EPYC 7643. Market segments are Desktop versus Server/Workstation. Production status is End-of-life versus Active. Release dates are 2017-10-04 versus 2021-03-14. The multiplier is unlocked on the i7-8700K and locked on the EPYC 7643.