Intel Core i5-8400H vs Intel Xeon E3-1585L v5 Comparison

The Intel Core i5-8400H and Intel Xeon E3-1585L v5 are both 45-watt, four-core, eight-thread processors aimed at very different market segments, yet they share a socket. The data shows a consistent performance advantage for the Xeon part across every benchmark recorded, despite the Core i5 having a higher boost clock. This head-to-head comparison reveals how architectural generation and feature sets can outweigh raw clock speed in determining real-world throughput.

Head-to-Head Benchmarks

The benchmark results are unambiguous: the Intel Xeon E3-1585L v5 wins all six recorded comparisons. In Cinebench R15 multi-core, the Xeon scores 693 against the Core i5-8400H's 644, a delta of -7.1% from the Core i5's perspective. The single-core test in R15 shows a similar gap, with the Xeon at 97 and the Core i5 at 90, a -7.2% difference. This pattern holds across every Cinebench version tested.

Moving to Cinebench R20, the Xeon again leads in multi-core with 2888 versus 2684, and in single-core with 407 versus 378. Both represent a -7.1% delta. The most recent Cinebench R23 results reinforce this trend: the Xeon posts 6878 in multi-core and 971 in single-core, while the Core i5 manages 6392 and 902 respectively, again a -7.1% gap. The consistency of this delta across all tests suggests a fundamental throughput advantage rather than a workload-specific quirk.

Notably, the Core i5-8400H has additional Geekbench scores not present for the Xeon: 3656 multi-core and 1281 single-core. However, these cannot be directly compared since the Xeon lacks corresponding Geekbench entries. The overall average benchmark score tells a similar story: the Core i5 averages 2003, while the Xeon averages 1989, a difference of less than 1%. This near-parity in average score, despite the Xeon winning every head-to-head, reflects the different benchmark suites available for each processor.

The Core i5's nearest rivals include the AMD Ryzen 7 2800H at 2002 (a 0.1% delta) and the Intel Xeon D-1712TR at 2004 (-0.1%). The Xeon's closest competitor is the Intel Xeon E3-1285L v4 at 1991 (-0.1%). These rival relationships place both processors in the same performance tier, with the Core i5 at the 45th percentile of all CPUs and the Xeon at the 44th percentile.

Architecture Differences

The two processors come from different architectural generations. The Core i5-8400H is built on Coffee Lake, specifically the Coffee Lake-H codename, while the Xeon E3-1585L v5 uses Skylake, with the Skylake-H codename. Both use a 14 nm process node from Intel, so the transistor size is identical. However, the die size differs substantially: the Core i5 measures 126 mm², while the Xeon is significantly larger at 171 mm². The Xeon also has a stated transistor count of 2,300 million, a figure not provided for the Core i5.

Cache configurations diverge as well. Both have 64 KB of L1 cache per core and 256 KB of L2 cache per core. The shared L3 cache, however, favors the Core i5: it has 12 MB shared, while the Xeon has only 8 MB shared. This 4 MB difference in L3 could theoretically benefit the Core i5 in cache-sensitive workloads, yet the benchmark data shows the Xeon winning regardless, indicating other factors dominate.

Clock speeds present a mixed picture. The Core i5 has a base clock of 2.50 GHz and a boost clock of 4.10 GHz. The Xeon runs at a higher base of 3.00 GHz but a lower boost of 3.70 GHz. The 0.4 GHz boost advantage for the Core i5 does not translate into benchmark wins, suggesting the Xeon's higher sustained base clock and other architectural traits are more impactful. Memory support also differs: the Core i5 supports only DDR4, while the Xeon supports both DDR3 and DDR4. The Xeon is explicitly rated for dual-channel memory with a bandwidth of 34.1 GB/s; the Core i5's memory bus and bandwidth are not specified. ECC memory is supported by the Xeon but not the Core i5.

Integrated graphics are a major differentiator. The Core i5 uses UHD 630, while the Xeon employs the more powerful Iris Pro Graphics P580. The Xeon's market segment is Server/Workstation, whereas the Core i5 targets Mobile. Both are end-of-life products, with the Core i5 released in April 2018 and the Xeon in May 2016. The Xeon carries a launch MSRP of $445; the Core i5 has no listed launch MSRP. Neither processor has an unlocked multiplier.

The Verdict

The data points decisively to the Intel Xeon E3-1585L v5 as the stronger performer in every recorded benchmark. Across six Cinebench tests spanning R15, R20, and R23, the Xeon leads by a consistent 7.1-7.2%. This is not a marginal victory; it is a uniform advantage that suggests the Xeon's higher base clock and server-class design deliver more usable throughput than the Core i5's higher boost clock and larger L3 cache can compensate for.

The Core i5-8400H does hold one advantage in the specification sheet: 12 MB of shared L3 cache versus the Xeon's 8 MB. It also has a 0.4 GHz higher boost clock. For workloads that are highly cache-sensitive or that benefit from short bursts of high single-thread speed, the Core i5 could theoretically close the gap, but the benchmark data does not show this happening in Cinebench. The Xeon wins both multi-core and single-core tests, indicating its architectural efficiency outweighs the Core i5's raw clock headroom.

The average benchmark scores are nearly identical, with the Core i5 at 2003 and the Xeon at 1989. This near-tie in average, contrasted with the Xeon's clean sweep of head-to-head tests, suggests the Core i5's additional Geekbench scores pull its average up, but those tests are not directly comparable. For users choosing between these two end-of-life processors, the Xeon E3-1585L v5 is the clear pick based on benchmark performance, provided its feature set (ECC memory, dual-channel DDR3/DDR4 support) is compatible with the application. The Core i5-8400H is only preferable if the larger L3 cache or the mobile-oriented UHD 630 graphics are specific requirements, and even then the performance deficit is a known cost.

FAQ

Q: Which processor wins in multi-core Cinebench R23?

A: The Intel Xeon E3-1585L v5 wins with a score of 6878, compared to the Intel Core i5-8400H's 6392, a 7.1% difference.

Q: Does the Core i5-8400H have a higher boost clock than the Xeon?

A: Yes, the Core i5-8400H boosts to 4.10 GHz, while the Xeon E3-1585L v5 boosts to 3.70 GHz. Despite this, the Xeon wins every single-core benchmark recorded.

Q: Do both processors support ECC memory?

A: No. The Intel Xeon E3-1585L v5 supports ECC memory, while the Intel Core i5-8400H does not.

Q: What is the L3 cache difference between the two?

A: The Core i5-8400H has 12 MB of shared L3 cache, while the Xeon E3-1585L v5 has 8 MB of shared L3 cache.

Q: How do their average benchmark scores compare?

A: The Core i5-8400H averages 2003, and the Xeon E3-1585L v5 averages 1989, a difference of less than 1%.

Q: Which processor has a larger die size?

A: The Xeon E3-1585L v5 has a die size of 171 mm², whereas the Core i5-8400H measures 126 mm².

Where Each One Wins

The Intel Xeon E3-1585L v5 wins in every directly comparable benchmark category. It leads in Cinebench R15 multi-core (693 vs 644), R15 single-core (97 vs 90), R20 multi-core (2888 vs 2684), R20 single-core (407 vs 378), R23 multi-core (6878 vs 6392), and R23 single-core (971 vs 902). This makes it the superior choice for any workload captured by Cinebench, which typically reflects rendering and general CPU compute. Its higher base clock of 3.00 GHz versus 2.50 GHz likely contributes to this sustained performance advantage.

The Intel Core i5-8400H does not win any head-to-head benchmark, but it has advantages that are not captured in the direct comparisons. It has a larger L3 cache at 12 MB versus 8 MB, which could benefit certain cache-heavy applications. It also has a higher boost clock of 4.10 GHz versus 3.70 GHz, which may help in short, single-threaded bursts that do not sustain long enough to be caught by Cinebench's scoring. Additionally, the Core i5 has Geekbench scores (3656 multi-core, 1281 single-core) that are not available for the Xeon, so its performance in that specific test suite remains unmeasured for comparison. For mobile applications, the Core i5's UHD 630 graphics may be sufficient, whereas the Xeon's Iris Pro Graphics P580 targets a different use case.

Specification Differences

The two processors differ in several specification fields. The Core i5-8400H uses the Coffee Lake architecture with the Coffee Lake-H codename, while the Xeon E3-1585L v5 uses Skylake with the Skylake-H codename. The Xeon has a die size of 171 mm² and 2,300 million transistors; the Core i5 has a smaller 126 mm² die with no transistor count listed. The L3 cache differs, with the Core i5 offering 12 MB shared and the Xeon offering 8 MB shared. Base clocks are 2.50 GHz for the Core i5 and 3.00 GHz for the Xeon, while boost clocks are 4.10 GHz and 3.70 GHz respectively. The Core i5 supports only DDR4 memory, while the Xeon supports both DDR3 and DDR4, with dual-channel memory and 34.1 GB/s bandwidth specified for the Xeon. ECC memory is supported only by the Xeon. The integrated graphics differ: UHD 630 on the Core i5 versus Iris Pro Graphics P580 on the Xeon. The market segments differ, with the Core i5 being Mobile and the Xeon being Server/Workstation. The Xeon has a launch MSRP of $445; the Core i5 has none listed. The Core i5 was released in April 2018, and the Xeon in May 2016. Both are end-of-life products with locked multipliers, and both use the Intel BGA 1440 socket.