Intel Core i5-8400H vs Intel Xeon E3-1285L v4 Comparison

The Intel Core i5-8400H and the Intel Xeon E3-1285L v4 are both 4-core, 8-thread Intel processors, but they target entirely different market segments: one is a mobile Coffee Lake part, the other a server/workstation Broadwell chip. Benchmark results show a consistent, if narrow, advantage for the older Xeon across every test, despite the i5-8400H’s higher boost clock and newer architecture.

Head-to-Head Benchmarks

The data is unambiguous: the Intel Xeon E3-1285L v4 wins all six head-to-head comparisons. In Cinebench R15, the Xeon scores 693 in multi-core against the i5-8400H’s 644, a delta of -7.1%. The single-core test follows the same pattern, with the Xeon at 97 versus 90, a -7.2% difference. These margins are small in absolute terms but consistent, suggesting the Xeon’s higher base clock is doing the heavy lifting.

Moving to Cinebench R20, the Xeon’s multi-core score of 2891 beats the i5-8400H’s 2684, again by -7.2%. The single-core result is 407 versus 378, a -7.1% gap. The pattern holds in Cinebench R23: the Xeon posts 6884 multi-core and 971 single-core, while the i5-8400H manages 6392 and 902, respectively. Both R23 deltas sit at -7.1%. There is no test where the i5-8400H pulls ahead; the Xeon’s advantage is uniform, ranging narrowly between -7.1% and -7.2% across all workloads.

This consistency is notable because the i5-8400H has a higher boost clock of 4.10 GHz versus the Xeon’s 3.80 GHz. The Xeon’s 3.40 GHz base clock, however, is substantially higher than the i5-8400H’s 2.50 GHz base. In sustained multi-core workloads, where boost clocks are less sustainable, the Xeon’s higher base frequency appears to be the decisive factor. The i5-8400H’s average benchmark score of 2003 places it at the 45th percentile of all CPUs, while the Xeon’s 1991 average sits at the 44th percentile, meaning these two chips are essentially peers in the broader CPU landscape despite the Xeon’s head-to-head sweep.

Architecture Differences

The two processors come from different Intel microarchitectures and eras. The i5-8400H is built on Coffee Lake, specifically the Coffee Lake-H variant, and was released in April 2018. It uses the Intel BGA 1440 socket, indicating a soldered mobile design. The Xeon E3-1285L v4 is a Broadwell-DT part, released in June 2015, and uses the older Intel Socket 1150, a standard desktop/server socket.

Both are fabricated on Intel’s 14 nm process, but the Xeon’s die is larger at 160 mm² and contains 1,400 million transistors, while the i5-8400H’s die is 126 mm² with transistor count not listed. The Xeon’s larger die likely reflects its integrated Iris Pro P6300 graphics, a more powerful GPU than the i5-8400H’s UHD 630. Both chips share 64 KB of L1 and 256 KB of L2 cache per core, but the L3 cache differs significantly: the i5-8400H has 12 MB shared, while the Xeon has only 6 MB shared. Despite having half the L3 cache, the Xeon still wins all benchmarks, suggesting cache size is not the bottleneck in these tests.

Memory support is another major divider. The i5-8400H supports DDR4 memory, while the Xeon E3-1285L v4 supports DDR3, with a dual-channel memory bus and a listed memory bandwidth of 29.9 GB/s. The i5-8400H’s memory bus and bandwidth are not specified in the data. The Xeon also supports ECC memory, which the i5-8400H does not. PCIe support is listed as Gen 3 for the Xeon, but is not specified for the i5-8400H. The Xeon’s market segment is Server/Workstation, whereas the i5-8400H is explicitly a Mobile part, which explains the socket and memory differences despite both being end-of-life products.

FAQ

Q: Which processor has a higher multi-core benchmark score?

A: The Intel Xeon E3-1285L v4 wins every multi-core test. It scores 693 vs 644 in Cinebench R15, 2891 vs 2684 in R20, and 6884 vs 6392 in R23, each time with a delta of about -7.1% relative to the i5-8400H.

Q: Does the i5-8400H have a higher clock speed?

A: The i5-8400H has a higher boost clock at 4.10 GHz compared to the Xeon’s 3.80 GHz. However, the Xeon has a much higher base clock at 3.40 GHz versus the i5-8400H’s 2.50 GHz.

Q: Which processor supports ECC memory?

A: Only the Intel Xeon E3-1285L v4 supports ECC memory. The i5-8400H does not have ECC support listed.

Q: How do these processors compare in average benchmark scores?

A: The i5-8400H has an average benchmark score of 2003, placing it at the 45th percentile, while the Xeon E3-1285L v4 has an average score of 1991, placing it at the 44th percentile. The nearest rival to the i5-8400H is the AMD Ryzen 7 2800H with a delta of 0.1%, and the nearest rival to the Xeon is the AMD Ryzen 5 1500X with a delta of 0%.

Q: What are the integrated graphics on each chip?

A: The i5-8400H includes Intel UHD 630 graphics, while the Xeon E3-1285L v4 includes Intel Iris Pro P6300 graphics.

Q: Which processor has more L3 cache?

A: The i5-8400H has 12 MB of shared L3 cache, which is double the Xeon E3-1285L v4’s 6 MB of shared L3 cache.

Specification Differences

The two CPUs differ across nearly every specification category. The i5-8400H has a base clock of 2.50 GHz and a boost clock of 4.10 GHz, while the Xeon E3-1285L v4 operates at 3.40 GHz base and 3.80 GHz boost. The Xeon’s TDP is 65 watts, higher than the i5-8400H’s 45 watts, reflecting its desktop/server heritage. The sockets are incompatible: the i5-8400H uses Intel BGA 1440, and the Xeon uses Intel Socket 1150.

The architecture and codename differ, with Coffee Lake-H versus Broadwell-DT. The Xeon’s die is larger at 160 mm² with 1,400 million transistors, while the i5-8400H is 126 mm² with no transistor count given. L3 cache is 12 MB on the i5-8400H versus 6 MB on the Xeon. Memory support diverges on type (DDR4 vs DDR3), bus (unspecified vs dual-channel), bandwidth (unspecified vs 29.9 GB/s), and ECC (false vs true). The Xeon also lists PCIe Gen 3 support, while the i5-8400H does not list PCIe. Integrated graphics differ (UHD 630 vs Iris Pro P6300), as do market segments (Mobile vs Server/Workstation) and release dates (April 2018 vs June 2015). The Xeon has a launch MSRP of $445; the i5-8400H has no listed launch MSRP.

The Verdict

The data presents a clear picture for buyers choosing between these two end-of-life processors. The Intel Xeon E3-1285L v4 is the faster chip in every benchmark, winning all six head-to-head tests with margins between -7.1% and -7.2%. Its advantage is most pronounced in single-core workloads, where it scores 971 in Cinebench R23 versus the i5-8400H’s 902, a gap that suggests better responsiveness in lightly threaded applications. The Xeon’s higher base clock of 3.40 GHz compared to the i5-8400H’s 2.50 GHz is the likely driver, especially in sustained workloads where boost clocks taper off.

However, the i5-8400H is not without merit. It offers double the L3 cache (12 MB vs 6 MB), a higher boost clock (4.10 GHz vs 3.80 GHz), and a lower TDP (45 watts vs 65 watts), making it more suitable for thermally constrained mobile environments. Its DDR4 memory support is more modern than the Xeon’s DDR3. But the Xeon’s ECC memory support and server/workstation positioning make it the more robust choice for reliability-focused builds. The average benchmark scores are nearly identical (2003 vs 1991), but the Xeon’s consistent head-to-head sweep gives it the edge for pure performance. The i5-8400H’s percentile ranking of 45th is only one point higher than the Xeon’s 44th, so neither chip offers a meaningful advantage in the broader CPU hierarchy.

Where Each One Wins

The Intel Xeon E3-1285L v4 wins in every benchmark category, making it the clear choice for users prioritizing raw compute performance. Its victories span both multi-core and single-core tests, from Cinebench R15 to R23. The Xeon’s higher base clock and ECC memory support position it for workstation tasks like rendering, compilation, or server workloads where stability and sustained throughput matter more than power efficiency. With a launch MSRP of $445, it was positioned as a professional-grade part, and the benchmark data justifies that classification.

The Intel Core i5-8400H, despite losing all head-to-head tests, has specific advantages that matter in its intended mobile segment. Its lower 45-watt TDP makes it more suitable for laptops and compact systems where cooling is limited. Its 12 MB of L3 cache, double the Xeon’s, could benefit certain cache-sensitive workloads, even if the benchmark suite does not show it. The higher boost clock of 4.10 GHz means that in short, bursty single-threaded tasks, the i5-8400H may close the gap, though the data shows it still trails the Xeon in the single-core tests. Its modern DDR4 memory support is a significant advantage for new system builds, as DDR3 is increasingly scarce. The i5-8400H is the better choice for a mobile or low-power system, while the Xeon is the better choice for a performance-focused desktop or server, assuming the higher TDP and older memory technology are acceptable trade-offs.