Intel Core i5-8400T vs Intel Xeon E3-1280 v5 Comparison

FAQ

Q: Which processor has more cores?

A: The Intel Core i5-8400T has 6 cores and 6 threads, while the Intel Xeon E3-1280 v5 has 4 cores and 8 threads. The Xeon relies on Hyper-Threading to reach 8 threads, while the i5 has no multithreading.

Q: Which processor has a higher boost clock?

A: The Xeon E3-1280 v5 boosts up to 4.00 GHz, while the Core i5-8400T boosts up to 3.30 GHz. The Xeon also has a much higher base clock at 3.70 GHz compared to 1700.00 MHz (which is 1.70 GHz) for the i5.

Q: Which processor supports ECC memory?

A: Only the Intel Xeon E3-1280 v5 supports ECC memory. The Core i5-8400T does not have ECC support. This is a key differentiator for workstation or server use.

Q: Are both processors compatible with the same socket?

A: Yes, both processors use Intel Socket 1151. However, the Xeon is based on the Skylake architecture, while the i5 is based on Coffee Lake, which are different generations of the socket.

Q: Which processor has a higher average benchmark score?

A: The Xeon E3-1280 v5 has an average benchmark score of 2029, while the Core i5-8400T has an average benchmark score of 2001. The difference is about 1.4% in favor of the Xeon.

Q: Which processor includes integrated graphics?

A: Only the Core i5-8400T includes integrated graphics: UHD Graphics 630. The Xeon E3-1280 v5 has no integrated graphics, which is typical for a server/workstation part.

Architecture Differences

The Intel Xeon E3-1280 v5 belongs to the Skylake-DT generation, built on Intel's 14 nm process with a die size of 122 mm² and 1,750 million transistors. The Core i5-8400T is a Coffee Lake part, also on 14 nm, but with a larger die at 154 mm². The transistor count for the i5 is not recorded in the database. The Xeon's smaller die with more transistors per area reflects its higher-end positioning within the Skylake generation.

The Xeon E3-1280 v5 has 4 cores and 8 threads, while the i5-8400T has 6 cores and 6 threads. The Xeon uses simultaneous multithreading to double its thread count, whereas the i5 has no such capability. This means the Xeon can handle 8 concurrent threads but only 4 physical cores, while the i5 has more physical cores but fewer total threads.

Cache configurations differ notably. Both have 64 KB of L1 and 256 KB of L2 per core, but the L3 cache is 8 MB shared on the Xeon versus 9 MB shared on the i5. The i5's larger L3 cache compensates for its lack of multithreading, giving each physical core more shared cache in practice.

Memory support is DDR4 for both, with dual-channel memory buses. The i5-8400T has a recorded memory bandwidth of 42.7 GB/s, while the Xeon's bandwidth is not listed. ECC memory is supported only on the Xeon, reinforcing its server/workstation market segment. The i5 is a desktop part with integrated UHD Graphics 630, while the Xeon has no integrated graphics.

Both use PCIe Gen 3 with 16 lanes from the CPU. The Xeon is marked as end-of-life with a release date of October 2015, while the i5 was released in April 2018 and is also end-of-life. The Xeon's launch MSRP is $612, and the i5's launch MSRP is $182. Neither has an unlocked multiplier.

The Verdict

The benchmark data is unambiguous: the Intel Xeon E3-1280 v5 wins all six recorded head-to-head tests against the Core i5-8400T. In Cinebench R15, R20, and R23, both multicore and singlecore, the Xeon leads by a margin between 11.2% and 11.7%. The largest single advantage is 11.7% in multicore workloads, where the Xeon scores 707, 2946, and 7015 in R15, R20, and R23 respectively, versus 633, 2638, and 6282 for the i5.

Who should pick the Xeon E3-1280 v5? Users who need ECC memory support for data integrity, those who prioritize single-threaded performance (the Xeon leads by 11.2% to 11.7% in singlecore tests), and anyone running heavily threaded workloads that benefit from 8 threads despite only 4 cores. The Xeon's server/workstation market segment and its higher boost clock of 4.00 GHz make it the stronger compute part.

Who should pick the Core i5-8400T? Users who need integrated graphics for a system without a discrete GPU, those who value lower power consumption (35 W TDP versus 80 W for the Xeon), and anyone who prefers more physical cores (6 versus 4) for workloads that scale poorly with multithreading. The i5 also has a larger L3 cache at 9 MB versus 8 MB.

The average benchmark scores are nearly identical: 2029 for the Xeon and 2001 for the i5. This means the i5's extra cores and larger cache nearly close the gap, but not enough to overcome the Xeon's higher clocks and multithreading advantage. For raw compute per benchmark, the Xeon is the winner; for integrated graphics and efficiency, the i5 is the choice.

Specification Differences

The two processors differ in several key fields. Core count: 4 for the Xeon versus 6 for the i5. Thread count: 8 for the Xeon versus 6 for the i5. Base clock: 3.70 GHz for the Xeon versus 1700.00 MHz (1.70 GHz) for the i5. Boost clock: 4.00 GHz for the Xeon versus 3.30 GHz for the i5. TDP: 80 W for the Xeon versus 35 W for the i5.

Architecture and generation: Skylake (Skylake-DT) for the Xeon versus Coffee Lake for the i5. Die size: 122 mm² for the Xeon versus 154 mm² for the i5. Transistor count: 1,750 million for the Xeon, not recorded for the i5. L3 cache: 8 MB shared for the Xeon versus 9 MB shared for the i5.

Memory bandwidth: not listed for the Xeon, 42.7 GB/s for the i5. ECC memory: supported on the Xeon, not on the i5. Integrated graphics: none on the Xeon, UHD Graphics 630 on the i5. Market segment: Server/Workstation for the Xeon, Desktop for the i5. Launch MSRP: $612 for the Xeon, $182 for the i5. Release date: October 2015 for the Xeon, April 2018 for the i5.

Both share: 14 nm process, Intel foundry, DDR4 memory, dual-channel memory bus, PCIe Gen 3 with 16 lanes, Intel Socket 1151, 64 KB L1 and 256 KB L2 per core, locked multiplier, and end-of-life production status.

Head-to-Head Benchmarks

The Xeon E3-1280 v5 wins every recorded head-to-head benchmark. In Cinebench R15 multicore, the Xeon scores 707 against 633 for the i5, a delta of 11.7%. In R15 singlecore, the Xeon scores 99 against 89, a delta of 11.2%. The pattern continues in R20: multicore 2946 versus 2638 (11.7% delta), singlecore 415 versus 372 (11.6% delta). In R23, the Xeon leads with 7015 versus 6282 multicore (11.7% delta) and 990 versus 886 singlecore (11.7% delta).

The consistency of these margins is striking. Across all six tests, the Xeon's advantage ranges narrowly from 11.2% to 11.7%. This suggests a fundamental clock speed and efficiency advantage rather than a workload-specific edge. The Xeon's boost clock of 4.00 GHz versus 3.30 GHz for the i5, combined with its 8 threads versus 6, explains the uniform lead.

The i5-8400T has additional Geekbench scores recorded: 4011 multicore and 1100 singlecore. The Xeon has no Geekbench results in the database, so no comparison is possible on that test. The absence of Geekbench data for the Xeon is notable, as it limits direct comparison on that popular benchmark.

The wins tally is 6 for the Xeon and 0 for the i5. The nearest rivals for the Xeon include the Xeon E3-1260L v5 (identical average score of 2029) and the Core i7-5775R (2031, 0.1% higher). The i5's nearest rivals include the Ryzen 7 2800H (2002, 0% delta) and the Core i5-8400H (2003, 0.1% higher). These rival scores show both processors sit in a crowded midrange band.

Where Each One Wins

The Xeon E3-1280 v5 wins in all recorded benchmark tests, so its strengths are clear. It excels in single-threaded performance, as shown by its 11.2% to 11.7% lead across R15, R20, and R23 singlecore tests. This makes it better for applications that depend on high clock speeds per core, such as older games, lightly threaded productivity apps, or database queries that execute serially.

The Xeon also wins in multicore scenarios, despite having fewer physical cores. Its 8 threads, combined with a 4.00 GHz boost clock, outperform the i5's 6 threads at 3.30 GHz. The multicore margins are consistently 11.7%, slightly higher than the singlecore margins. This indicates that the Xeon's multithreading advantage stacks on top of its clock advantage in parallel workloads.

ECC memory support gives the Xeon a qualitative edge for error-correcting workloads, though no benchmark in the database measures this. The server/workstation market segment suggests reliability features that the desktop i5 lacks.

The i5-8400T wins in areas not captured by the Cinebench suite. Its integrated UHD Graphics 630 means it can power a display without a discrete GPU, which the Xeon cannot do. The 35 W TDP is less than half the Xeon's 80 W, implying significantly lower power draw and heat output, which matters for compact or passively cooled systems.

The i5's 6 physical cores could benefit workloads that are sensitive to core count rather than thread count, though the benchmark data does not show this advantage. Its larger 9 MB L3 cache versus 8 MB may help with cache-heavy workloads, but again, the recorded benchmarks do not reflect a win. The i5's additional Geekbench scores (4011 multicore, 1100 singlecore) provide data points that the Xeon lacks, but without a direct comparison, they only show the i5's absolute level.

For users seeking raw compute performance as measured by Cinebench, the Xeon is the clear winner. For users needing integrated graphics, lower power consumption, or more physical cores, the i5 has qualitative advantages that the benchmark scores do not capture.