AMD EPYC 7451 vs Intel Core i9-11900KB Comparison

Head-to-Head Benchmarks

The recorded benchmark data shows a clean sweep for the AMD EPYC 7451 across all six Cinebench tests. The largest advantage appears in Cinebench R15 multi-core, where the EPYC 7451 scores 2061 against the Core i9-11900KB's 1946, a 5.9% lead. Single-core performance tells a similar story: the EPYC 7451 posts 290 in Cinebench R15 single-core, beating the i9-11900KB's 274 by 5.8%. These margins are consistent, not incidental.

In Cinebench R20, the EPYC 7451 delivers 8589 multi-core points versus 8112 for the Intel part, again a 5.9% advantage. The single-core R20 result follows the same pattern: 1212 for the EPYC versus 1145 for the i9-11900KB, a 5.9% gap. The most recent test in the database, Cinebench R23, shows the EPYC 7451 at 20450 multi-core and 2887 single-core, while the i9-11900KB manages 19316 and 2727 respectively. Each of those is a 5.9% delta in favor of the AMD processor.

The uniformity of these deltas is noteworthy. Across every test, from R15 to R23, the percentage difference remains at 5.9% except for the R15 single-core case, which shows 5.8%. This suggests the performance relationship between these two chips is stable regardless of workload type, whether the test scales across many threads or focuses on a single core. The EPYC 7451 wins all six head-to-head comparisons, with the Intel part recording zero victories.

When placed against the broader database, both processors sit at the 61st percentile among all CPUs. The EPYC 7451's average benchmark score is 5915, while the i9-11900KB averages 5587. That difference of 328 points represents roughly a 5.9% overall gap, consistent with the individual test results. The nearest rival to the EPYC 7451 is the Intel Core i9-9920X, which scores 5917, a delta of 0%. The Intel Xeon W-2170B scores 5985, putting it 1.2% ahead of the EPYC. On the AMD side, the EPYC 7401P scores 5814 (1.7% behind) and the Intel Xeon E-2388G scores 5805 (1.9% behind). For the i9-11900KB, the closest competitor is the Intel Atom x7433RE at 5601, which is 0.2% ahead. The Intel Core i7-12700T scores 5606 (0.3% ahead), the AMD Ryzen 7 PRO 3700 scores 5610 (0.4% ahead), and the Intel Celeron G6900 scores 5561 (0.5% behind).

Architecture Differences

The two processors come from fundamentally different design philosophies. The AMD EPYC 7451 uses the Zen architecture on the Naples codename, built on a 14 nm process at GlobalFoundries. It packs 24 cores and 48 threads, a configuration aimed at server and workstation workloads. The Intel Core i9-11900KB uses Tiger Lake (Tiger Lake-H) architecture on a 10 nm process at Intel, with 8 cores and 16 threads, targeting mobile platforms. The transistor count for the EPYC 7451 is recorded at 4,800 million, while the Intel part's transistor count is not listed in the database. Die sizes differ as well: the EPYC 7451 measures 213 mm², the i9-11900KB measures 190 mm².

Cache hierarchies are markedly different. The EPYC 7451 provides 96 KB of L1 cache per core, 512 KB of L2 per core, and 64 MB of shared L3 cache. The i9-11900KB offers 80 KB of L1 per core, a larger 1.25 MB of L2 per core, but only 24 MB of shared L3. This means the AMD part has substantially more total cache, especially at the L3 level, which can benefit workloads with large working sets. The Intel part's larger per-core L2 might help with certain access patterns, but the overall cache capacity favors the EPYC.

Memory support also diverges sharply. Both support DDR4, but the EPYC 7451 uses an eight-channel memory bus with a theoretical bandwidth of 170.6 GB/s, while the i9-11900KB uses a dual-channel bus with 51.2 GB/s. That is a 3.3x difference in memory bandwidth, a critical factor for server applications that move large amounts of data. ECC memory is supported on the EPYC 7451 but not on the i9-11900KB. PCIe generations differ: the EPYC 7451 uses Gen 3, while the i9-11900KB uses Gen 4 with 20 lanes from the CPU.

The Intel part includes integrated graphics (UHD Graphics 750), while the EPYC 7451 has none. This makes sense given their market segments: the EPYC is a server/workstation part, the i9-11900KB is a mobile processor. The EPYC 7451 uses AMD Socket SP3, the Intel part uses BGA 1787. Both have unlocked multipliers. The EPYC 7451 was released on 2017-06-28 and remains in active production, while the i9-11900KB has no release date recorded and is marked as end-of-life. The EPYC 7451's part number is PS7451BDVHCAF; the i9-11900KB's is SRKU4. The Intel part has a launch MSRP of $539.

The Verdict

The data points to a clear performance winner: the AMD EPYC 7451. It beats the Intel Core i9-11900KB in every recorded benchmark, with margins between 5.8% and 5.9%. This is a consistent, repeatable advantage across single-core and multi-core tests. The EPYC 7451 also offers 24 cores versus 8, 48 threads versus 16, and dramatically more memory bandwidth (170.6 GB/s versus 51.2 GB/s). For workloads that scale with cores, threads, or memory throughput, the EPYC 7451 is the stronger choice based on the recorded data.

The i9-11900KB, however, has its own advantages that the benchmark scores do not capture. It runs at a higher base clock (3.30 GHz versus 2.30 GHz) and a much higher boost clock (5.30 GHz versus 3.20 GHz). It uses newer PCIe Gen 4, includes integrated graphics, and has a far lower TDP of 65 watts versus 180 watts. For mobile or power-constrained environments, the Intel part is clearly designed for a different purpose. The EPYC 7451's 180 watt TDP suggests it needs substantial cooling and power delivery, while the i9-11900KB can operate in thinner chassis.

The production status also matters. The EPYC 7451 is active, meaning it can still be sourced for new systems. The i9-11900KB is end-of-life, which may limit availability. The EPYC 7451 supports ECC memory, a requirement for many server deployments, while the i9-11900KB does not. The database shows both processors at the same 61st percentile, but the EPYC 7451's average score is higher, and it sits among rivals like the Core i9-9920X and Xeon W-2170B, whereas the i9-11900KB's nearest rivals include lower-end parts like the Atom x7433RE and Celeron G6900.

Specification Differences

The following fields differ between the two processors:

• Cores: 24 (EPYC 7451) versus 8 (i9-11900KB)
• Threads: 48 versus 16
• Base clock: 2.30 GHz versus 3.30 GHz
• Boost clock: 3.20 GHz versus 5.30 GHz
• TDP: 180 watts versus 65 watts
• Socket: AMD Socket SP3 versus Intel BGA 1787
• Architecture: Zen versus Tiger Lake
• Codename: Naples versus Tiger Lake-H
• Process node: 14 nm versus 10 nm
• Foundry: GlobalFoundries versus Intel
• Transistors: 4,800 million versus not recorded
• Die size: 213 mm² versus 190 mm²
• L1 cache: 96 KB per core versus 80 KB per core
• L2 cache: 512 KB per core versus 1.25 MB per core
• L3 cache: 64 MB shared versus 24 MB shared
• Memory bus: Eight-channel versus dual-channel
• Memory bandwidth: 170.6 GB/s versus 51.2 GB/s
• ECC memory: Supported versus not supported
• PCIe: Gen 3 versus Gen 4, 20 lanes
• Integrated graphics: None versus UHD Graphics 750
• Market segment: Server/Workstation versus Mobile
• Production status: Active versus End-of-life
• Release date: 2017-06-28 versus not recorded
• Launch MSRP: Not recorded versus $539
• Part number: PS7451BDVHCAF versus SRKU4

FAQ

Q: Which processor wins in multi-core performance?

A: The AMD EPYC 7451 wins all three multi-core Cinebench tests. It scores 2061 in R15, 8589 in R20, and 20450 in R23, each about 5.9% ahead of the Intel Core i9-11900KB's 1946, 8112, and 19316.

Q: Does the Intel Core i9-11900KB win any benchmark?

A: No. The head-to-head data shows the EPYC 7451 winning all six tests, with the i9-11900KB recording zero victories.

Q: What is the memory bandwidth difference?

A: The EPYC 7451 supports eight-channel DDR4 with 170.6 GB/s of bandwidth. The i9-11900KB uses dual-channel DDR4 with 51.2 GB/s. That is a 3.3x difference in theoretical bandwidth.

Q: Which processor supports ECC memory?

A: Only the AMD EPYC 7451 supports ECC memory. The Intel Core i9-11900KB does not list ECC support in the database.

Q: Are these processors in the same performance percentile?

A: Yes, both sit at the 61st percentile among all CPUs. However, the EPYC 7451 has a higher average benchmark score of 5915 versus 5587 for the i9-11900KB.

Q: What is the production status of each?

A: The EPYC 7451 is listed as active production, while the i9-11900KB is end-of-life.

Where Each One Wins

The AMD EPYC 7451 wins in every measured benchmark, but the nature of its wins points to specific use cases. Its 24 cores and 48 threads, combined with 170.6 GB/s of memory bandwidth, make it suited for heavily threaded server workloads, virtualization, database processing, and scientific computing. The 64 MB of L3 cache helps with large datasets. Its active production status and ECC support make it viable for new server builds. The 180 watt TDP implies a system with robust cooling and power delivery, typical of rack-mounted servers or workstations.

The Intel Core i9-11900KB, despite losing all six head-to-head tests, has clear advantages in other dimensions. Its 65 watt TDP and mobile segment designation indicate it is built for laptops or compact systems where power efficiency is critical. The 5.30 GHz boost clock is significantly higher than the EPYC's 3.20 GHz, which can benefit lightly threaded tasks that depend on raw clock speed. The integrated UHD Graphics 750 means no separate GPU is required for basic display output, a feature the EPYC 7451 lacks entirely. PCIe Gen 4 support provides newer connectivity options, and the dual-channel memory configuration is simpler and cheaper to implement in a mobile chassis. The i9-11900KB's launch MSRP of $539 and end-of-life status suggest it may appear in discounted or clearance systems, though the data does not include pricing comparisons.

For users choosing between these two, the decision comes down to workload and platform. If the task requires many cores, high memory throughput, ECC reliability, and server-grade features, the EPYC 7451 is the clear pick from the recorded data. If the priority is a low-power, mobile-ready processor with high boost clocks and integrated graphics, the i9-11900KB serves that role, even though it trails in every Cinebench test. The EPYC 7451's six wins and higher average score make it the stronger performer in the database, but the i9-11900KB's specifications reveal a different design target that benchmark results alone do not fully describe.