Intel Core i5-8400T vs Intel Xeon E3-1245 v5 Comparison

Head-to-Head Benchmarks

The recorded data shows a clean sweep for the Intel Xeon E3-1245 v5 across every benchmark measured in this comparison. The Xeon wins all six head-to-head tests, with the Core i5-8400T trailing by margins between 7.3% and 8% depending on the workload. The most consistent gap appears in multi-threaded Cinebench tests, where the Xeon holds a 7.9% advantage across R15, R20, and R23 variants. Single-threaded performance tells a similar story, with the Xeon leading by 7.3% in Cinebench R15 single-core and 8% in Cinebench R23 single-core.

Starting with Cinebench R15 multi-core, the Xeon E3-1245 v5 scores 687 against the i5-8400T's 633, a delta of 7.9%. That pattern repeats almost exactly in Cinebench R20 multi-core (2865 vs 2638, again 7.9%) and Cinebench R23 multi-core (6822 vs 6282, again 7.9%). The consistency of these margins suggests a stable performance differential that scales with thread count rather than a workload-specific quirk. The Xeon's 8 threads versus the i5's 6 threads likely explains this uniform gap, though the database records only the scores themselves.

Single-threaded results are nearly as uniform. Cinebench R15 single-core shows 96 for the Xeon versus 89 for the i5, a 7.3% lead. Cinebench R20 single-core repeats the 7.9% pattern (404 vs 372), and Cinebench R23 single-core shows the widest gap at 8% (963 vs 886). The Xeon's higher base clock and boost clock, recorded at 3.50 GHz and 3.90 GHz respectively against the i5's 1.70 GHz base and 3.30 GHz boost, provide the likely cause for this consistent single-thread advantage.

The i5-8400T does have a measurable edge in Geekbench, where it scores 4011 multi-core and 1100 single-core, but the Xeon has no recorded Geekbench results in this database, so no direct head-to-head comparison is possible. The absence of Geekbench data for the Xeon means the only comparable metrics are the six Cinebench tests, all of which favor the Xeon. The wins tally reflects this: the Xeon takes all six wins, the i5 takes zero.

Average benchmark scores place the two processors close overall: the i5-8400T averages 2001 across its recorded tests, while the Xeon averages 1973. This is a narrow 1.4% difference favoring the i5, but the average includes Geekbench scores that the Xeon lacks, making the comparison uneven. Within the shared Cinebench suite, the Xeon is consistently ahead.

Percentile rankings are nearly identical, with the i5 at the 45th percentile and the Xeon at the 44th percentile against all CPUs in the database. Both processors sit near the middle of the overall performance distribution, meaning neither is an outlier at either end of the spectrum. The nearest rival data reinforces this: the i5-8400T's closest competitor is the AMD Ryzen 7 2800H with an average score of 2002 and a 0% delta, while the Xeon's closest rival is the Intel Core i7-10810U at 1971 with a 0.1% delta.

FAQ

Q: Which processor wins the most benchmarks in this comparison?

A: The Intel Xeon E3-1245 v5 wins all six recorded head-to-head tests. The Core i5-8400T does not win any of the six shared benchmarks.

Q: How large is the Xeon's multi-core advantage in Cinebench R23?

A: The Xeon scores 6822 against the i5's 6282, a lead of 7.9%. The same 7.9% margin appears in Cinebench R15 multi-core (687 vs 633) and Cinebench R20 multi-core (2865 vs 2638).

Q: Does the Core i5-8400T have any benchmark where it leads?

A: The i5 has a higher average benchmark score (2001 vs 1973) and a higher Geekbench multi-core score (4011), but the Xeon has no Geekbench results recorded, so these cannot be compared directly. In all shared Cinebench tests, the Xeon leads.

Q: What is the single-threaded performance gap?

A: The Xeon leads by 7.3% in Cinebench R15 single-core (96 vs 89), 7.9% in Cinebench R20 single-core (404 vs 372), and 8% in Cinebench R23 single-core (963 vs 886).

Q: How do these processors rank against all CPUs in the database?

A: The i5-8400T sits at the 45th percentile and the Xeon at the 44th percentile. Both are mid-pack performers with near-identical overall standings.

Q: What is the average benchmark score for each processor?

A: The i5-8400T averages 2001 points, while the Xeon averages 1973 points. The i5's average is slightly higher, but this includes Geekbench results that the Xeon lacks.

The Verdict

The data points decisively toward the Intel Xeon E3-1245 v5 for users who prioritize raw compute performance in the applications measured. Every single Cinebench test, both single-core and multi-core, shows the Xeon ahead by roughly 7 to 8 percent. The consistency of this margin across six different tests indicates a reliable, repeatable performance advantage rather than a workload-specific outlier. For rendering tasks, simulation workloads, or any application that scales with Cinebench-style multi-threaded performance, the Xeon is the clear choice based on the recorded measurements.

The Core i5-8400T, however, is not without merit. Its average benchmark score of 2001 exceeds the Xeon's 1973, and its Geekbench multi-core score of 4011 demonstrates strong performance in that specific test, though the Xeon lacks comparable Geekbench data. The i5 also operates at a 35 W TDP against the Xeon's 80 W TDP, making it the more power-efficient option for systems where thermal constraints matter. Users building a low-power desktop or a compact system may prefer the i5 despite its lower Cinebench scores.

The Xeon's support for ECC memory is another differentiating factor. The database records the Xeon as supporting ECC memory while the i5 does not, making the Xeon the appropriate choice for workstation or server applications where data integrity is critical. The Xeon also supports both DDR3 and DDR4 memory, while the i5 supports only DDR4, offering greater flexibility in memory selection.

For the majority of compute-intensive tasks, the Xeon E3-1245 v5 is the better processor. The 7.9% multi-core advantage and 8% single-core advantage in Cinebench R23 translate into meaningful real-world gains in threaded workloads. The i5-8400T is the pick for low-power or ECC-free builds where its higher average score and lower TDP are more valuable than the Xeon's consistent Cinebench edge.

Specification Differences

The two processors differ in several core specifications. The Core i5-8400T has 6 cores and 6 threads, while the Xeon E3-1245 v5 has 4 cores and 8 threads. The Xeon's Hyper-Threading support gives it two extra threads despite having two fewer physical cores.

Clock speeds differ substantially. The i5-8400T has a base clock of 1.70 GHz and a boost clock of 3.30 GHz. The Xeon starts at 3.50 GHz base and boosts to 3.90 GHz. The Xeon's clocks are significantly higher in both modes, which explains its single-threaded advantage.

Thermal design power is a major differentiator. The i5-8400T is rated at 35 W, while the Xeon is rated at 80 W. This makes the i5 far more suitable for power-constrained or fanless designs, while the Xeon requires more substantial cooling.

Cache configurations differ in L3 capacity. The i5 has 9 MB of shared L3 cache, while the Xeon has 8 MB. Both have identical per-core L1 (64 KB) and L2 (256 KB) caches.

Memory support varies. The i5 supports DDR4 only, while the Xeon supports both DDR3 and DDR4. Memory bandwidth also differs: the i5 is rated at 42.7 GB/s and the Xeon at 34.1 GB/s, both on dual-channel buses.

ECC memory support is exclusive to the Xeon. The i5 does not support ECC, while the Xeon does, a key distinction for server and workstation reliability requirements.

Integrated graphics differ as well. The i5 features UHD Graphics 630, while the Xeon has HD Graphics P530. Both are Intel integrated solutions, but they are different models.

The Xeon has a larger transistor count at 1,750 million versus no recorded count for the i5, and a smaller die size at 122 mm² compared to the i5's 154 mm².

Architecture Differences

The processors come from different architectural generations. The Core i5-8400T is based on Coffee Lake architecture, while the Xeon E3-1245 v5 uses Skylake architecture with the codename Skylake-DT. The i5 belongs to the Core i5 (Coffee Lake) generation, and the Xeon belongs to the Xeon E3 (Skylake-DT) generation.

Both processors are manufactured on a 14 nm process node by Intel. The i5's die size is 154 mm², while the Xeon's is 122 mm². The Xeon's transistor count is recorded at 1,750 million, while the i5's is not listed.

The Xeon was released earlier, with a release date of October 2015, while the i5 came later in April 2018. Both processors are end-of-life and use the Intel Socket 1151.

PCIe support is identical: both offer Gen 3 with 16 lanes (CPU only). Neither processor has an unlocked multiplier.

The market segments differ. The i5 is classified as a desktop processor, while the Xeon is classified as server/workstation. This positioning aligns with the Xeon's ECC support and the i5's lower TDP.

Where Each One Wins

The Xeon E3-1245 v5 wins in every application that resembles the Cinebench workloads. Multi-threaded rendering, video encoding, 3D modeling, and any task that scales across 8 threads will see the Xeon's 7.9% advantage over the i5 in Cinebench R15, R20, and R23 multi-core tests. Single-threaded tasks also favor the Xeon by 7.3% to 8%, so even lightly threaded applications like legacy software or spreadsheet work will run faster on the Xeon.

The i5-8400T wins in power-sensitive scenarios. Its 35 W TDP versus the Xeon's 80 W TDP makes it the better fit for small form factor builds, all-in-one systems, or any configuration where cooling and power budgets are tight. The i5's higher memory bandwidth (42.7 GB/s vs 34.1 GB/s) and larger L3 cache (9 MB vs 8 MB) could provide advantages in memory-bound workloads, though the recorded benchmarks do not isolate these factors.

For ECC memory requirements, the Xeon is the only option. Users building a file server, NAS, or workstation that demands error-correcting memory must choose the Xeon. Similarly, the Xeon's support for both DDR3 and DDR4 memory gives it flexibility for upgrades or repurposing older memory modules.

The i5's Geekbench multi-core score of 4011 suggests strong performance in that specific benchmark suite, though without Xeon Geekbench data, this cannot be compared directly. The i5's higher average benchmark score of 2001 versus the Xeon's 1973 also indicates that, across all recorded tests, the i5 holds a slight overall edge when including tests the Xeon does not share.

Users who prioritize raw compute throughput in Cinebench-style workloads should select the Xeon E3-1245 v5. Users who prioritize power efficiency, lower thermal output, or ECC-free operation should select the Core i5-8400T. The Xeon wins the performance battle in every shared test; the i5 wins the efficiency and flexibility arguments.