Intel Core i5-2405S vs Intel Xeon W3565 Comparison

Head-to-Head Benchmarks

The benchmark data presents an unusually close contest between the Intel Xeon W3565 and the Intel Core i5-2405S. Across five Cinebench tests, the Core i5-2405S wins every single comparison, yet the margins are so narrow that the two processors effectively trade blows at the statistical noise level. The largest gap appears in Cinebench R20 single-core, where the i5-2405S scores 171 against the Xeon's 170, a delta of -0.6%. That is a one-point difference on a scale where both chips are clearly operating in the same performance tier.

The multicore results tell a similar story. In Cinebench R15, the i5-2405S edges ahead with 291 points versus 290 for the Xeon W3565, a margin of -0.3%. The R20 multicore test shows 1213 against 1212, and R23 multicore shows 2890 against 2888 — each time the i5-2405S wins by a hair. The R23 single-core test follows the pattern: 408 for the i5-2405S, 407 for the Xeon, a -0.2% delta. What is remarkable is not that one chip consistently wins, but that the differences are so small that they would be imperceptible in real-world workloads. The Xeon W3565's higher base clock of 3.20 GHz and boost clock of 3.47 GHz do not translate into meaningful benchmark superiority over the i5-2405S's 2.50 GHz base and 3.30 GHz boost.

Looking at the aggregate picture, the Xeon W3565 posts an average benchmark score of 993, while the i5-2405S posts 991. The Xeon's nearest rivals include the Intel Core i7-965 and AMD Phenom II X6 1065T, both at exactly 993, and the Intel Core i7-960 also at 993, with the Intel Core i3-8130U at 994 (-0.1%). The i5-2405S's nearest rivals are nearly identical: the i7-960, i7-965, and Xeon W3565 all sit at 993 with a -0.2% delta, and the Phenom II X6 1065T matches at 993. Both processors land at the 27th percentile among all CPUs, indicating they occupy the same performance bracket despite their architectural differences.

The Geekbench results, available only for the i5-2405S, show a multicore score of 1425 and a single-core score of 541. While no direct Xeon comparison exists in this test, the score placement reinforces that the i5-2405S is a competent performer for its era. The head-to-head table confirms the sweep: the i5-2405S wins all five Cinebench contests, with the Xeon W3565 recording zero wins. However, the largest delta between the two is just -0.6%, which is far below what any user would notice in daily operation.

FAQ

Q: Which processor has a higher average benchmark score?

A: The Intel Xeon W3565 has an average benchmark score of 993, while the Intel Core i5-2405S has an average of 991. The difference is two points, placing both at the 27th percentile among all CPUs.

Q: Does the Xeon W3565 win any head-to-head benchmark?

A: No. The head-to-head data shows the Core i5-2405S winning all five Cinebench tests, with the Xeon W3565 recording zero wins. The closest margin is -0.1% in Cinebench R20 multicore and R23 multicore.

Q: How do the core and thread counts differ between the two?

A: Both processors have 4 cores. The Xeon W3565 supports 8 threads via Hyper-Threading, while the Core i5-2405S supports 4 threads. Despite the Xeon's thread advantage, the i5-2405S still wins every multicore benchmark.

Q: What is the TDP difference between the two chips?

A: The Xeon W3565 has a TDP of 130 watts, while the Core i5-2405S has a TDP of 65 watts. The i5-2405S draws half the power of the Xeon while delivering essentially identical benchmark performance.

Q: Which processor supports ECC memory?

A: The Xeon W3565 supports ECC memory, while the Core i5-2405S does not. This is a key differentiator for server or workstation use where data integrity is critical.

Q: Do both processors have integrated graphics?

A: No. The Core i5-2405S includes Intel HD 3000 integrated graphics, while the Xeon W3565 has no integrated graphics at all. This means the Xeon requires a discrete GPU for any display output.

The Verdict

The data presents a clear conclusion: for pure computational performance, the Intel Core i5-2405S is effectively equal to, and marginally ahead of, the Intel Xeon W3565. The i5-2405S wins every head-to-head benchmark, albeit by fractions of a percent, and achieves this with half the TDP (65 watts versus 130 watts). The Xeon W3565's only advantages lie in its 8-thread capability and ECC memory support, but these do not translate into benchmark wins in the Cinebench suite. Users prioritizing raw performance per watt should choose the i5-2405S, as it delivers the same or slightly better scores while consuming 65 watts less power. Users requiring ECC memory for mission-critical workloads must choose the Xeon W3565, as the i5-2405S lacks this feature entirely. The Xeon also requires a discrete GPU, while the i5-2405S has Intel HD 3000 integrated graphics, making the i5-2405S a more self-contained solution for a desktop system.

Specification Differences

The two processors diverge on nearly every specification except core count, L1 cache, and L2 cache. Both have 4 cores, 64 KB of L1 cache per core, and 256 KB of L2 cache per core. The Xeon W3565 has 8 threads versus 4 threads on the i5-2405S. The Xeon's base clock is 3.20 GHz and boost clock is 3.47 GHz, while the i5-2405S runs at 2.50 GHz base and 3.30 GHz boost. TDP is a major difference: 130 watts for the Xeon, 65 watts for the i5-2405S. The Xeon uses Intel Socket 1366, while the i5-2405S uses Intel Socket 1155. L3 cache is 8 MB shared on the Xeon and 6 MB shared on the i5-2405S. Memory support is triple-channel DDR3 on the Xeon and dual-channel DDR3 on the i5-2405S. The Xeon supports ECC memory; the i5-2405S does not. PCIe generation differs as well: Gen 2 on the Xeon, Gen 3 with 16 lanes (CPU only) on the i5-2405S. The i5-2405S has integrated Intel HD 3000 graphics; the Xeon has none. Market segments are Server/Workstation for the Xeon and Desktop for the i5-2405S. Release dates are 2009-10-31 for the Xeon and 2011-05-21 for the i5-2405S, making the i5-2405S approximately eighteen months newer.

Architecture Differences

The architectural gap between these two chips is substantial. The Xeon W3565 uses the Nehalem architecture with the Bloomfield codename, built on a 45 nm process node at Intel's foundry. It contains 731 million transistors on a 263 mm² die. The Core i5-2405S uses the Sandy Bridge architecture with the same codename, built on a 32 nm process node, also at Intel's foundry. It contains 1,160 million transistors on a 216 mm² die — more transistors in a smaller physical area, reflecting the newer manufacturing process. The Xeon's generation is listed as "Xeon (Bloomfield)," while the i5-2405S is "Core i5 (Sandy Bridge)." The Xeon's larger L3 cache of 8 MB shared versus 6 MB shared on the i5-2405S may help in some server workloads, but the benchmark data does not show a consistent advantage. The i5-2405S's smaller 32 nm process node contributes to its far lower TDP of 65 watts versus 130 watts. Both processors have their L1 cache at 64 KB per core and L2 at 256 KB per core, but the i5-2405S integrates graphics (Intel HD 3000) directly on the die, whereas the Xeon has no integrated graphics. The Xeon's triple-channel memory bus provides higher theoretical memory bandwidth than the i5-2405S's dual-channel bus, though no bandwidth figures are available in the data. The i5-2405S supports PCIe Gen 3 with 16 lanes (CPU only), while the Xeon supports PCIe Gen 2. Both processors are end-of-life and have locked multipliers.

Where Each One Wins

The Intel Core i5-2405S wins in every benchmark category measured, but the practical significance depends on the use case. For single-core workloads, the i5-2405S holds a slim edge in Cinebench R20 (171 vs 170) and R23 (408 vs 407). For multicore workloads, the i5-2405S wins Cinebench R15 (291 vs 290), R20 (1213 vs 1212), and R23 (2890 vs 2888). The i5-2405S also wins decisively on power efficiency, with a 65-watt TDP versus 130 watts for the Xeon — a 50% reduction in power draw. The i5-2405S offers integrated graphics, making it a viable option for a desktop build without a discrete GPU. The Xeon W3565, by contrast, wins on thread count (8 versus 4), which could theoretically benefit heavily parallel server workloads, although the benchmark data does not reflect any such advantage in Cinebench. The Xeon also wins on ECC memory support, making it the only choice for systems requiring error-correcting memory. The Xeon's triple-channel memory bus provides a wider memory path, though no performance delta is shown in the benchmarks. For a workstation or server application where ECC is mandatory and power consumption is less of a concern, the Xeon W3565 is the appropriate pick. For a desktop system where power efficiency, integrated graphics, and equal-or-better benchmark scores matter, the Core i5-2405S is the clear winner based on the data. The 27th percentile ranking for both CPUs confirms they sit in the same performance class, but the i5-2405S achieves that standing with significantly less power and newer architecture.