AMD EPYC 7443P vs Intel Xeon 638 Comparison

The AMD EPYC 7443P and Intel Xeon 638 are both server-class processors aimed at demanding workloads, yet they approach performance from very different architectural directions. The EPYC 7443P, a 24-core Zen 3 part from the EPYC 7003 series, edges out the 16-core Granite Rapids-based Xeon 638 in most benchmark comparisons, winning 13 of the 17 head-to-head tests. The Xeon 638 counters with four wins, including decisive single-thread and floating-point victories. The data reveals a nuanced picture: the AMD part dominates in integer-heavy and data-processing tasks, while the Intel chip shows clear strengths in specialized instruction throughput and raw single-core speed. Neither processor is a universal winner, and the choice hinges on workload profile rather than a simple performance hierarchy.

The Verdict

From the benchmark data, the AMD EPYC 7443P is the stronger all-around performer. Its average benchmark score of 81661 places it in the 96th percentile of all CPUs, while the Intel Xeon 638 sits at 80723 in the 95th percentile. The EPYC 7443P leads in the Cinebench suite across all versions—R15, R20, and R23—for both multi-core and single-core tests, with consistent 2.6-2.7% advantages. It also dominates in PassMark integer math (232632 vs 184884, a 25.8% margin), data compression (820859 vs 725818, 13.1% ahead), and data encryption (57263 vs 36030, a massive 58.9% gap). For workloads built around integer arithmetic, database operations, or encryption, the EPYC 7443P is the clear recommendation.

The Intel Xeon 638, however, wins the single-thread PassMark test decisively, scoring 3670 against the EPYC's 2907—a 20.8% advantage. It also leads in floating-point math (144757 vs 129932, 10.2% ahead) and extended instructions (56498 vs 48213, 14.7% ahead). This makes the Xeon 638 the better choice for workloads that rely heavily on floating-point calculations, like scientific simulations or certain rendering tasks, and for applications that scale poorly across cores but benefit from fast single-thread execution. The Xeon 638 also has an unlocked multiplier, which the EPYC 7443P lacks, though the data does not quantify overclocking gains. Buyers should pick the EPYC 7443P for general server consolidation, virtualization, or data-centric tasks, and the Xeon 638 when single-thread latency or floating-point throughput is paramount.

Architecture Differences

The two processors represent distinct design philosophies and fabrication generations. The AMD EPYC 7443P uses the Zen 3 architecture, codenamed Milan, built on a 7 nm process at TSMC. It packs 24 cores and 48 threads, with a base clock of 2.85 GHz and a boost clock of 4.00 GHz. The Intel Xeon 638 uses the Granite Rapids architecture, also its codename, fabricated on Intel's 5 nm process. It offers fewer resources—16 cores and 32 threads—but runs at higher clocks: 3.20 GHz base and 4.80 GHz boost. The core count difference is substantial: the EPYC has 50% more cores and threads, yet the Xeon compensates with a 20% higher boost clock.

Cache hierarchies diverge sharply. The EPYC 7443P provides 64 KB of L1 per core, 512 KB of L2 per core, and a large 128 MB shared L3 cache. The Xeon 638 offers 112 KB of L1 per core and 2 MB of L2 per core—larger per-core allocations—but its shared L3 is only 72 MB. This smaller L3 could impact workloads with large working sets, though the EPYC's larger cache is shared across more cores. Memory support also differs: the EPYC uses DDR4 over an eight-channel memory bus, while the Xeon uses DDR5 over a quad-channel bus. Despite these differences, both achieve identical memory bandwidth of 204.8 GB/s, a notable parity given the different channel counts and memory generations.

Process node and die size tell a story of manufacturing scale. The EPYC 7443P is built from four chiplets, each 81 mm², totaling 16,600 million transistors. The Xeon 638 is a monolithic 598 mm² die, with no transistor count listed. The EPYC's chiplet design and 7 nm TSMC process contrast with Intel's larger single-die approach on 5 nm. PCIe capabilities also differ: the EPYC offers Gen 4 with 128 lanes (CPU only), while the Xeon provides Gen 5 with 80 lanes. This means the EPYC supports more total I/O lanes, but the Xeon's lanes are newer and potentially faster per lane. Both support ECC memory, which is expected for server platforms. The Xeon 638 has no integrated graphics, and the EPYC 7443P also lists none.

Head-to-Head Benchmarks

The Cinebench results are remarkably consistent, with the AMD EPYC 7443P winning every test by nearly identical margins. In Cinebench R15, the EPYC scores 4881 multi-core versus the Xeon's 4757, a 2.6% lead; in single-core, it wins 689 to 671, a 2.7% edge. Cinebench R20 shows the same pattern: 20341 vs 19824 multi-core and 2871 vs 2798 single-core, both 2.6% ahead. Cinebench R23 follows suit, with the EPYC at 48433 vs 47202 multi-core and 6837 vs 6663 single-core. These margins are small but consistent, suggesting the EPYC's extra cores provide a modest multi-core advantage while its single-core performance also edges out the higher-clocked Xeon.

PassMark results reveal where each chip excels. The EPYC 7443P wins integer math decisively, scoring 232632 against 184884, a 25.8% advantage. Data compression also favors the EPYC heavily: 820859 vs 725818, a 13.1% lead. Most striking is data encryption, where the EPYC scores 57263 versus the Xeon's 36030—a 58.9% gap that suggests a significant architectural advantage in cryptographic workloads. The EPYC also wins random string sorting (95581 vs 74318, 28.6% ahead), find prime numbers (410 vs 381, 7.6% ahead), and multithread tests (56981 vs 55651, 2.4% ahead). Physics tests are nearly tied, with the EPYC at 4748 vs 4704, only 0.9% ahead.

The Intel Xeon 638's wins are concentrated but pronounced. In single-thread PassMark, it scores 3670 versus the EPYC's 2907, a 20.8% lead that is the largest single margin in either direction. Floating-point math also goes to Intel: 144757 vs 129932, a 10.2% advantage. Extended instructions favor the Xeon too, with a score of 56498 against 48213, a 14.7% lead. These results indicate that while the EPYC handles integer and data-heavy tasks with ease, the Xeon's newer architecture and higher clocks give it a clear edge in floating-point and single-threaded execution.

FAQ

Q: Which processor has better multi-core performance?

A: The AMD EPYC 7443P wins all three Cinebench multi-core tests (R15, R20, R23) by 2.6% margins, and also leads PassMark multithread by 2.4% (56981 vs 55651). Its higher core count of 24 versus 16 contributes to these wins.

Q: Is the Intel Xeon 638 faster in single-threaded tasks?

A: Yes, in PassMark single-thread tests, the Xeon 638 scores 3670 versus the EPYC 7443P's 2907, a 20.8% advantage. However, in Cinebench single-core tests, the EPYC wins all three by 2.6-2.7%, so the result depends on the benchmark methodology.

Q: How do the two compare in memory bandwidth?

A: Both processors achieve identical memory bandwidth of 204.8 GB/s, despite the EPYC 7443P using eight-channel DDR4 and the Xeon 638 using quad-channel DDR5.

Q: Which CPU is better for encryption workloads?

A: The AMD EPYC 7443P is dramatically better, scoring 57263 in PassMark data encryption versus the Xeon 638's 36030, a 58.9% advantage.

Q: What about floating-point performance?

A: The Intel Xeon 638 wins PassMark floating-point math with 144757 versus the EPYC's 129932, a 10.2% lead. It also wins extended instructions by 14.7%.

Q: Do both processors support ECC memory?

A: Yes, both the AMD EPYC 7443P and Intel Xeon 638 support ECC memory, which is standard for server/workstation platforms.

Where Each One Wins

The AMD EPYC 7443P is the clear winner for integer-heavy workloads. Its 25.8% lead in PassMark integer math and 28.6% advantage in random string sorting point to strong performance in database operations, general server processing, and data transformation tasks. Data compression is another strength, with a 13.1% edge, making it suitable for file servers or backup systems. The 58.9% encryption advantage is standout, positioning the EPYC for secure communications, VPN gateways, or any workload requiring heavy cryptographic processing. Its consistent Cinebench wins, including single-core, suggest well-rounded performance that benefits multi-threaded applications like video rendering or code compilation.

The Intel Xeon 638 wins where floating-point and single-thread speed matter most. Its 10.2% advantage in floating-point math could benefit scientific computing, financial modeling, or machine learning inference. The 14.7% lead in extended instructions suggests strong SIMD or specialized instruction performance, useful for vectorized workloads. The 20.8% single-thread PassMark win makes it attractive for legacy applications that stubbornly rely on single-core performance, or for latency-sensitive tasks where every clock cycle counts. Its higher boost clock of 4.80 GHz versus 4.00 GHz likely drives these wins, though the data does not explicitly confirm the mechanism.

Specification Differences

The AMD EPYC 7443P and Intel Xeon 638 differ across nearly every core specification. The EPYC has 24 cores and 48 threads, while the Xeon has 16 cores and 32 threads—a 50% core advantage for AMD. Clock speeds reverse this: the Xeon runs at 3.20 GHz base and 4.80 GHz boost, while the EPYC runs at 2.85 GHz base and 4.00 GHz boost. The EPYC's TDP is 200 watts, higher than the Xeon's 180 watts. Sockets are incompatible: AMD uses Socket SP3, Intel uses Socket 4710.

Cache configurations differ significantly. The EPYC provides 64 KB L1 per core, 512 KB L2 per core, and 128 MB shared L3. The Xeon offers 112 KB L1 per core, 2 MB L2 per core, and 72 MB shared L3. The EPYC's larger total L3 (128 MB vs 72 MB) may benefit shared workloads, while the Xeon's larger per-core L2 could help single-threaded performance. Process nodes also differ: the EPYC is 7 nm at TSMC, the Xeon is 5 nm at Intel. The EPYC uses a 4x 81 mm² die design with 16,600 million transistors; the Xeon uses a 598 mm² die with no transistor count given.

Memory and I/O present further contrasts. The EPYC uses DDR4 with an eight-channel bus, while the Xeon uses DDR5 with a quad-channel bus; both achieve 204.8 GB/s bandwidth. PCIe support differs: the EPYC offers Gen 4 with 128 lanes, the Xeon offers Gen 5 with 80 lanes. The Xeon has an unlocked multiplier, while the EPYC does not. Release dates reflect different generations: the EPYC launched in March 2021, the Xeon in February 2026. The EPYC's launch MSRP is $1337, and the Xeon's is $899. Both are active production parts for the server/workstation market, both support ECC, and neither has integrated graphics.