Intel Core i5-9400 vs Intel Xeon E3-1285 v6 Comparison

Head-to-Head Benchmarks

The benchmark data for these two Intel Socket 1151 processors tells a remarkably consistent story. Across every Cinebench iteration recorded in the database, the Intel Xeon E3-1285 v6 finishes ahead of the Intel Core i5-9400. The margin is not trivial either; it is a sustained advantage that repeats in both single-core and multi-core workloads.

In Cinebench R15 multi-core, the Xeon E3-1285 v6 scores 818 against the i5-9400's 668. That is a 22.5% advantage. The single-core result is nearly identical in percentage terms, with the Xeon posting 115 versus 94, a 22.3% lead. The pattern holds in Cinebench R20: the Xeon scores 3409 in multi-core and 481 in single-core, while the i5-9400 manages 2784 and 392 respectively. These are deltas of 22.4% and 22.7%.

The newest Cinebench R23 results reinforce the trend. The Xeon E3-1285 v6 records 8119 in multi-core and 1146 in single-core. The Core i5-9400 finishes with 6629 and 935. The delta percentages are 22.5% and 22.6%, respectively. It is rare to see such a uniform spread across a benchmark suite, but the data shows the Xeon leading every single recorded test.

The database also includes Geekbench results for the i5-9400, which scores 5141 in multi-core and 1389 in single-core. The Xeon does not have a Geekbench entry in the recorded data, so no direct comparison is possible for that suite. However, the Cinebench results alone establish the performance hierarchy clearly.

Overall, the head-to-head table shows six wins for the Xeon E3-1285 v6 and zero for the Core i5-9400. The average benchmark score in the database reflects this gap: the Xeon sits at 2348, while the i5-9400 sits at 2254. That is a difference of roughly 4.2% in the aggregate score, even though the per-test deltas are much larger, because the aggregate includes different benchmark mixes.

What explains the Xeon's edge? The raw specifications point to clock speed. The Xeon E3-1285 v6 has a base clock of 4.10 GHz and a boost clock of 4.50 GHz. The Core i5-9400 operates at 2.90 GHz base and 4.10 GHz boost. Even though the i5-9400 has two additional physical cores (six versus four), the Xeon's higher clocks and Hyper-Threading (eight threads versus six) allow it to maintain a lead in every recorded test. The Xeon also draws more power, with a 79 W TDP against the i5-9400's 65 W, which is consistent with its higher clock rates.

The nearest rivals for each chip provide additional context. The Xeon E3-1285 v6's closest competitor in the database is the Intel Core i5-9600, which has an average score of 2354, putting the Xeon just 0.3% behind. The AMD Ryzen 5 2500X (2361, 0.5% behind) and Intel Xeon E-2226GE (2365, 0.7% behind) are also nearby. The Xeon's percentile ranking is 48, meaning it sits just below the midpoint of all CPUs in the database.

The Core i5-9400's nearest rival is the Intel Core i3-10305, with an average score of 2264, which is 0.4% ahead of the i5-9400. The Intel Core i7-1068NG7 (2259, 0.2% ahead) and Intel Core i7-10710U (2248, 0.3% behind) bracket it closely. The i5-9400's percentile ranking is 47, one point lower than the Xeon's 48.

The Verdict

The data is unambiguous: the Intel Xeon E3-1285 v6 is the faster processor in every benchmark the database records. If the sole criterion is raw Cinebench performance, the Xeon is the pick. It posts a 22.5% lead in R15 multi-core, 22.4% in R20 multi-core, and 22.5% in R23 multi-core. The single-core deltas are equally consistent at just over 22% across all three Cinebench versions.

Who should choose the Xeon E3-1285 v6? The market segment field identifies it as a Server/Workstation part. It supports ECC memory, which the Core i5-9400 does not. It has a higher TDP (79 W versus 65 W), which suggests it is designed for sustained workloads where the extra power draw is acceptable. The Xeon also has a higher base clock (4.10 GHz versus 2.90 GHz) and boost clock (4.50 GHz versus 4.10 GHz), making it the better choice for latency-sensitive or single-threaded tasks that cannot tolerate clock dips.

Who should choose the Core i5-9400? The i5-9400 is a Desktop part with six physical cores and six threads. It has a larger L3 cache (9 MB shared versus 8 MB shared on the Xeon). It also has a higher memory bandwidth rating of 42.7 GB/s, a figure not recorded for the Xeon. The i5-9400 is marked as end-of-life in the database, while the Xeon's production status is not listed. For users who prioritize the larger L3 cache or the desktop market segment, the i5-9400 is the relevant part. But the benchmark data does not show any performance area where the i5-9400 wins.

The percentile rankings are close: 48 for the Xeon versus 47 for the i5-9400. The average benchmark scores are 2348 and 2254, respectively. The Xeon's nearest rival, the Core i5-9600, is within 0.3%, so the Xeon is essentially tied with that chip. The i5-9400's nearest rival, the Core i3-10305, is 0.4% ahead, so the i5-9400 sits at the very edge of its performance tier.

FAQ

Q: Which CPU is faster in multi-core workloads?

A: The Intel Xeon E3-1285 v6 wins all three recorded multi-core tests. It scores 818 in Cinebench R15, 3409 in R20, and 8119 in R23, versus 668, 2784, and 6629 for the Core i5-9400. The deltas are 22.5%, 22.4%, and 22.5%, respectively.

Q: Is the single-core performance gap similar to the multi-core gap?

A: Yes. The Xeon leads by 22.3% in Cinebench R15 single-core (115 versus 94), 22.7% in R20 single-core (481 versus 392), and 22.6% in R23 single-core (1146 versus 935).

Q: Does the Core i5-9400 have more cores?

A: Yes, the i5-9400 has six cores and six threads. The Xeon E3-1285 v6 has four cores and eight threads. Despite having fewer physical cores, the Xeon still wins every benchmark due to its higher clock speeds.

Q: What about memory support and cache?

A: Both support DDR4 dual-channel memory. The Xeon supports ECC memory, while the i5-9400 does not. The i5-9400 has a larger L3 cache (9 MB shared versus 8 MB shared) and a recorded memory bandwidth of 42.7 GB/s, which the Xeon does not have in the database.

Q: How do these chips compare to their nearest rivals?

A: The Xeon E3-1285 v6 is 0.3% behind the Intel Core i5-9600, 0.5% behind the AMD Ryzen 5 2500X, and 0.7% behind the Intel Xeon E-2226GE in average score. The Core i5-9400 is 0.2% behind the Intel Core i7-1068NG7, 0.3% behind the Intel Core i7-10710U, and 0.4% behind the Intel Core i3-10305.

Q: What are the release dates?

A: The Xeon E3-1285 v6 was released on 2017-07-31. The Core i5-9400 was released on 2018-10-18.

Specification Differences

The two processors differ in several key specification fields. The Xeon E3-1285 v6 has 4 cores and 8 threads, while the Core i5-9400 has 6 cores and 6 threads. The base clock is 4.10 GHz on the Xeon versus 2.90 GHz on the i5-9400. The boost clock is 4.50 GHz on the Xeon versus 4.10 GHz on the i5-9400. The TDP is 79 W for the Xeon and 65 W for the i5-9400.

The L3 cache differs: the Xeon has 8 MB shared, while the i5-9400 has 9 MB shared. The i5-9400 has a recorded memory bandwidth of 42.7 GB/s; the Xeon has no memory bandwidth figure in the database. ECC memory support is present on the Xeon and absent on the i5-9400. The integrated graphics differ: the Xeon uses HD Graphics P630, while the i5-9400 uses UHD 630.

The market segments are different: the Xeon is listed as Server/Workstation, while the i5-9400 is listed as Desktop. The i5-9400 has a production status of End-of-life; the Xeon's production status is not recorded. The release dates are 2017-07-31 for the Xeon and 2018-10-18 for the i5-9400. The part numbers are SR373 for the Xeon and SR3X5 for the i5-9400. Neither chip has an unlocked multiplier.

Architecture Differences

Both processors are built on Intel's 14 nm process node and use the Intel Socket 1151. The Xeon E3-1285 v6 is based on the Kaby Lake architecture, specifically the Kaby Lake-DT codename, and belongs to the Xeon E3 generation. The Core i5-9400 is based on the Coffee Lake architecture, with the Coffee Lake codename, and belongs to the Core i5 (Coffee Lake Refresh) generation.

The Xeon has 1,400 million transistors and a die size of 160 mm². The i5-9400 does not have transistor count or die size recorded in the database. Both have identical L1 cache (64 KB per core) and L2 cache (256 KB per core). The L3 cache is 8 MB shared on the Xeon and 9 MB shared on the i5-9400.

Both processors support DDR4 memory in a dual-channel configuration. Both use PCIe Gen 3 with 16 lanes (CPU only). The memory bandwidth is recorded only for the i5-9400 at 42.7 GB/s. The Xeon supports ECC memory, a feature typically associated with server and workstation reliability requirements, while the i5-9400 does not.

The integrated graphics differ: HD Graphics P630 on the Xeon and UHD 630 on the i5-9400. The Xeon's market segment is Server/Workstation, while the i5-9400 is a Desktop part. The i5-9400 is marked end-of-life, while the Xeon's production status is not listed. These architectural choices reflect their intended roles: the Xeon prioritizes high clock speeds and ECC support for professional workloads, while the i5-9400 offers more physical cores and a larger L3 cache for desktop multitasking. The benchmark data, however, shows the Xeon's clock advantage and Hyper-Threading delivering superior results in every recorded Cinebench test.