Intel Xeon 638 vs Intel Xeon w5-2565X Comparison

The Intel Xeon 638 and Intel Xeon w5-2565X are both active, server/workstation processors that land in the same performance tier, with average benchmark scores of 80,723 and 80,671 respectively. The Xeon 638 edges ahead by 0.1%, a margin so thin that the two chips are effectively interchangeable in aggregate throughput. However, the distribution of wins across individual workloads tells a far more interesting story: the Xeon 638 takes 11 of 17 head-to-head benchmarks, while the w5-2565X secures 6, and the nature of those victories reveals distinct use-case strengths rather than a simple overall winner.

Where Each One Wins

The Intel Xeon 638 is the clear choice for single-threaded and latency-sensitive tasks. It wins every Cinebench iteration by exactly 7%, covering R15, R20, and R23 in both single-core and multi-core modes. Its single-core scores of 671 (R15), 2,798 (R20), and 6,663 (R23) consistently outpace the w5-2565X’s 627, 2,615, and 6,227. This pattern extends to PassMark’s single-thread test, where the Xeon 638 posts 3,670 versus 3,595, a 2.1% advantage. For workloads that hinge on per-core responsiveness—such as interactive rendering, legacy single-threaded applications, or lightly threaded simulation solvers—the Xeon 638 is the better fit.

The w5-2565X, by contrast, dominates in math-heavy and encryption-oriented workloads. It wins PassMark integer math (189,446 vs. 184,884, a 2.4% edge), floating-point math (147,644 vs. 144,757, a 2% edge), and extended instructions (58,976 vs. 56,498, a 4.2% edge). Data encryption also favors the w5-2565X (36,365 vs. 36,030, a 0.9% edge), as does data compression (726,133 vs. 725,818, essentially a tie at 0%). Random string sorting also goes to the w5-2565X by a negligible 0.1%. This makes the w5-2565X the stronger option for scientific computing, financial modeling, or any workload that stresses ALU/FMA pipelines and cryptographic operations.

The Xeon 638 reclaims the lead in two specialized PassMark tests with dramatic margins. Its find prime numbers score of 381 beats the w5-2565X’s 218 by 74.8%, a massive gap that points to superior integer division and branch handling. Similarly, the physics test shows a 79.4% advantage (4,704 vs. 2,622), indicating that the Xeon 638’s architecture handles rigid-body and particle simulations far more efficiently. For multi-threaded general throughput, the Xeon 638 also wins PassMark’s multithread test (55,651 vs. 51,897, a 7.2% edge), reinforcing its overall Cinebench dominance.

FAQ

Q: Which processor has the higher average benchmark score?

A: The Intel Xeon 638 has an average benchmark score of 80,723, which is 0.1% higher than the Intel Xeon w5-2565X’s 80,671.

Q: Does the Xeon 638 win all Cinebench tests?

A: Yes, the Xeon 638 wins every Cinebench R15, R20, and R23 benchmark, both single-core and multi-core, by a consistent 7% margin.

Q: Where does the Xeon w5-2565X outperform the Xeon 638?

A: The w5-2565X wins in PassMark integer math, floating-point math, extended instructions, data encryption, data compression, and random string sorting, with margins ranging from 0% to 4.2%.

Q: What is the biggest performance gap between the two?

A: The largest delta is in PassMark physics, where the Xeon 638 scores 4,704 versus 2,622 for the w5-2565X, a 79.4% advantage.

Q: Are both processors in the same performance percentile?

A: Yes, both the Xeon 638 and the w5-2565X sit at the 95th percentile among all CPUs.

Q: Do both processors support the same memory type?

A: Both support DDR5 memory with ECC, but the Xeon 638 has a memory bandwidth of 204.8 GB/s compared to 153.6 GB/s for the w5-2565X.

Head-to-Head Benchmarks

The Cinebench suite is the strongest statement of the Xeon 638’s superiority. Across R15, R20, and R23, the Xeon 638 wins multi-core and single-core by exactly 7%. In Cinebench R23 multi-core, the Xeon 638 scores 47,202 against the w5-2565X’s 44,112, a difference of 3,090 points. The single-core R23 result is similarly decisive: 6,663 vs. 6,227. These margins are uniform, suggesting a per-clock efficiency advantage rather than a raw core-count effect, since the w5-2565X actually has more cores (18 vs. 16) yet still loses in multi-core workloads.

The PassMark multithread test reinforces this trend, with the Xeon 638 posting 55,651 versus 51,897, a 7.2% win. The physics test is the most lopsided result of the entire comparison: the Xeon 638’s 4,704 score is nearly double the w5-2565X’s 2,622, a 79.4% gap that cannot be explained by core count alone. Similarly, the find prime numbers test shows a 74.8% advantage for the Xeon 638 (381 vs. 218), indicating a fundamental architectural advantage in certain integer operations.

The w5-2565X’s wins are narrower and concentrated in modern math workloads. Its largest margin is in extended instructions (58,976 vs. 56,498, a 4.2% edge), followed by integer math (189,446 vs. 184,884, a 2.4% edge) and floating-point math (147,644 vs. 144,757, a 2% edge). These are meaningful for compute-heavy applications, but they are nowhere near the magnitude of the Xeon 638’s wins in physics and prime numbers. The w5-2565X also takes data compression (726,133 vs. 725,818) and data encryption (36,365 vs. 36,030), but the deltas are under 1%, making them statistical ties in practical terms.

Specification Differences

The two processors diverge on several core specifications. The Xeon 638 has 16 cores and 32 threads, while the w5-2565X has 18 cores and 36 threads. Both share the same base clock of 3.20 GHz and boost clock of 4.80 GHz. Thermal design power differs significantly: the Xeon 638 is rated at 180 W, while the w5-2565X draws 240 W. The w5-2565X delivers its higher core count and math performance at a 60 W penalty.

Memory bandwidth also favors the Xeon 638, which offers 204.8 GB/s versus 153.6 GB/s for the w5-2565X, despite both using quad-channel DDR5. PCIe lane counts differ as well: the Xeon 638 provides 80 Gen 5 lanes (CPU only), while the w5-2565X provides 64 Gen 5 lanes. The Xeon 638 uses Intel Socket 4710, whereas the w5-2565X uses Intel Socket 4677, so they are not drop-in interchangeable. Launch MSRP for the Xeon 638 is $899; launch MSRP for the w5-2565X is $1,339.

Architecture Differences

The Xeon 638 is built on Intel’s Granite Rapids architecture, specifically the Xeon 600 (Granite Rapids-WS) generation, and uses a 5 nm process node. Its die size is 598 mm². The w5-2565X is based on the older Sapphire Rapids architecture, part of the Xeon W (Sapphire Rapids) generation, and uses a 10 nm process node. This process difference likely explains the Xeon 638’s superior power efficiency and higher memory bandwidth, despite the w5-2565X having more cores.

Cache configurations differ substantially. The Xeon 638 has 112 KB of L1 cache per core and 2 MB of L2 cache per core, with a large 72 MB shared L3 cache. The w5-2565X has 80 KB of L1 cache per core and 2 MB of L2 cache per core, but only 37.5 MB of L3 cache. The Xeon 638’s 72 MB L3 is nearly double the w5-2565X’s 37.5 MB, which contributes to its wins in latency-sensitive and repeated-access workloads like Cinebench and physics simulations.

Both processors share several traits: they are Intel-manufactured, support ECC memory, have no integrated graphics, are multiplier-unlocked, and target the server/workstation segment. Both are listed as active in production. The Xeon 638 was released on 2026-02-01, while the w5-2565X launched earlier on 2024-08-23. Part numbers are SA2DN for the Xeon 638 and SRN4E for the w5-2565X.