Intel Core i5-8400T vs Intel Xeon E3-1240 v5 Comparison

FAQ

Q: Which processor has the higher average benchmark score?

A: The Intel Xeon E3-1240 v5 holds a higher average benchmark score of 2030, compared to the Intel Core i5-8400T's 2001. Both processors sit at the 45th percentile among all CPUs in the database.

Q: How large is the performance gap in multi-core workloads?

A: The Xeon leads by roughly 10.5% across all three multi-core Cinebench tests. In Cinebench R23 multi-core, the Xeon scores 7020 versus the i5-8400T's 6282, a difference of 738 points.

Q: Does the i5-8400T win any benchmark comparisons?

A: No. In the head-to-head data, the Xeon E3-1240 v5 wins all six recorded tests, covering both single-core and multi-core workloads across Cinebench R15, R20, and R23.

Q: What memory features differentiate these two CPUs?

A: The Xeon E3-1240 v5 supports both DDR3 and DDR4 memory and includes ECC memory support. The i5-8400T supports only DDR4 and does not offer ECC memory.

Q: Which chip has the higher boost clock speed?

A: The Xeon E3-1240 v5 boosts to 3.90 GHz, while the i5-8400T boosts to 3.30 GHz. The Xeon also has a higher base clock at 3.50 GHz versus 1.70 GHz.

Q: Are these processors still in production?

A: Both are end-of-life products. The i5-8400T was released in April 2018, while the Xeon E3-1240 v5 was released in October 2015.

Architecture Differences

The two chips come from different Intel microarchitectures, despite sharing the same 14 nm process node and Intel Socket 1151. The i5-8400T is built on Coffee Lake, while the Xeon E3-1240 v5 uses Skylake-DT. This architectural split explains several fundamental differences in their design goals.

The i5-8400T is a desktop-oriented part with 6 cores and 6 threads, operating without Hyper-Threading. Its base clock is remarkably low at 1.70 GHz, though it can boost to 3.30 GHz. This configuration, combined with a 35 W TDP, positions it as an energy-efficient desktop chip. The die size for the i5-8400T is 154 mm², and it integrates UHD Graphics 630, making it a self-contained solution for systems without a discrete GPU.

The Xeon E3-1240 v5 takes a different approach. It has 4 cores and 8 threads, using Hyper-Threading to double its thread count. Its base clock is substantially higher at 3.50 GHz, with a boost of 3.90 GHz. This comes at a cost: the TDP is 80 W, more than double that of the i5-8400T. The Xeon's die size is smaller at 122 mm², with 1,750 million transistors, and it has no integrated graphics, reflecting its server and workstation focus.

Cache layouts also differ. Both share 64 KB of L1 and 256 KB of L2 per core, but the L3 cache is 9 MB shared on the i5-8400T versus 8 MB shared on the Xeon. The Xeon's smaller L3, despite fewer cores, indicates a different balance between per-core resources and shared capacity.

Memory support is a key architectural divider. The Xeon supports both DDR3 and DDR4 in a dual-channel configuration, with memory bandwidth of 34.1 GB/s. The i5-8400T supports only DDR4, also dual-channel, but with a higher memory bandwidth of 42.7 GB/s. The Xeon's ECC memory support is a defining feature for reliability-focused workloads, which the i5-8400T lacks entirely.

The PCIe configuration is identical: Gen 3 with 16 lanes from the CPU. Both are locked multipliers, meaning neither supports overclocking. Their market segments differ, however, with the i5-8400T classified as Desktop and the Xeon as Server/Workstation.

Head-to-Head Benchmarks

The recorded benchmark data shows a consistent pattern: the Xeon E3-1240 v5 outperforms the i5-8400T across every test, with no wins for the i5-8400T.

In Cinebench R15 multi-core, the Xeon scores 707 against the i5-8400T's 633, a 10.5% advantage. The single-core result is similar: 99 versus 89, a 10.1% lead. This early gap suggests the Xeon's higher clocks provide a fundamental advantage that scales across workload types.

Moving to Cinebench R20, the Xeon's multi-core score is 2948 compared to 2638, again a 10.5% delta. Single-core shows 416 versus 372, a 10.6% difference. The consistency of these margins is notable; the Xeon maintains roughly a tenth-percent advantage regardless of the rendering workload.

Cinebench R23 reinforces the pattern. Multi-core scores are 7020 for the Xeon and 6282 for the i5-8400T, a 10.5% gap. Single-core is 991 versus 886, a 10.6% difference. Across all three Cinebench generations, the Xeon's winning margin hovers tightly between 10.1% and 10.6%, indicating a stable performance differential.

The Xeon's advantage comes despite having fewer physical cores (4 versus 6). Its higher base and boost clocks, plus Hyper-Threading, allow it to outperform the i5-8400T's larger core count. The i5-8400T's 6 cores cannot compensate for its low 1.70 GHz base clock and lack of multi-threading.

Interestingly, the i5-8400T has a higher memory bandwidth specification (42.7 GB/s versus 34.1 GB/s), yet the Xeon still wins all compute-bound tests. This suggests that memory bandwidth is not the limiting factor in these Cinebench workloads; clock speed and thread efficiency dominate.

Specification Differences

The two processors differ in nearly every key specification category. Here is a breakdown of where they diverge:

• Cores: 6 (i5-8400T) versus 4 (Xeon)
• Threads: 6 (i5-8400T) versus 8 (Xeon)
• Base clock: 1.70 GHz (i5-8400T) versus 3.50 GHz (Xeon)
• Boost clock: 3.30 GHz (i5-8400T) versus 3.90 GHz (Xeon)
• TDP: 35 W (i5-8400T) versus 80 W (Xeon)
• Architecture: Coffee Lake (i5-8400T) versus Skylake (Xeon)
• Codename: Coffee Lake (i5-8400T) versus Skylake-DT (Xeon)
• Generation: Core i5 (Coffee Lake) versus Xeon E3 (Skylake-DT)
• Transistors: Not listed (i5-8400T) versus 1,750 million (Xeon)
• Die size: 154 mm² (i5-8400T) versus 122 mm² (Xeon)
• L3 cache: 9 MB shared (i5-8400T) versus 8 MB shared (Xeon)
• Memory support: DDR4 only (i5-8400T) versus DDR3 and DDR4 (Xeon)
• Memory bandwidth: 42.7 GB/s (i5-8400T) versus 34.1 GB/s (Xeon)
• ECC memory: Not supported (i5-8400T) versus supported (Xeon)
• Integrated graphics: UHD Graphics 630 (i5-8400T) versus none (Xeon)
• Market segment: Desktop (i5-8400T) versus Server/Workstation (Xeon)
• Release date: April 2018 (i5-8400T) versus October 2015 (Xeon)
• Launch MSRP: $182 (i5-8400T) versus $282 (Xeon)
• Part number: SR3X6 (i5-8400T) versus SR2LD (Xeon)

The TDP difference is the most striking: 35 W versus 80 W means the Xeon consumes over twice the power budget, which explains its higher clock speeds. The i5-8400T compensates with a larger die and more L3 cache, but this does not translate into benchmark wins.

Where Each One Wins

Based solely on the recorded benchmark data, the Xeon E3-1240 v5 wins in every measurable compute category. Its strengths are most pronounced in single-core performance, where it leads by 10.1% to 10.6% across all Cinebench versions. This makes it the better choice for applications that rely heavily on single-threaded responsiveness, such as older software or lightly threaded workloads.

In multi-core tests, the Xeon also prevails, despite having fewer physical cores. Its Hyper-Threading and higher clocks allow it to sustain a 10.5% lead in every multi-core benchmark. For rendering tasks, video encoding, or compilation workloads that scale with threads, the Xeon's 8 threads outperform the i5-8400T's 6 threads.

The i5-8400T's only advantages lie in non-compute specifications. It has a higher memory bandwidth (42.7 GB/s versus 34.1 GB/s), which could benefit memory-intensive workloads not represented in the Cinebench suite. It also includes integrated graphics, eliminating the need for a discrete GPU in basic display scenarios. Its 35 W TDP makes it far more suitable for low-power or compact systems.

The Xeon's ECC memory support is a significant win for data integrity in server or workstation environments. For tasks where a single-bit memory error is unacceptable, such as financial modeling or scientific computing, this feature alone can justify the Xeon.

The Verdict

The data is unambiguous: the Intel Xeon E3-1240 v5 outperforms the Intel Core i5-8400T in every recorded benchmark. With a 10.5% lead across both single-core and multi-core Cinebench tests, the Xeon's higher clock speeds and Hyper-Threading overcome the i5-8400T's additional physical cores.

Users seeking maximum compute performance from the database's measurements should choose the Xeon E3-1240 v5. Its consistent wins across all six head-to-head benchmarks make it the stronger processor for rendering, single-threaded applications, and multi-threaded workloads alike. The ECC memory support adds a reliability layer that the i5-8400T cannot offer.

That said, the i5-8400T has a clear use case for power-constrained builds. Its 35 W TDP is less than half the Xeon's 80 W, and its integrated graphics allow for a simpler system configuration. For a compact desktop or a media server where performance per watt matters more than raw throughput, the i5-8400T is the sensible option.

The Xeon commands a higher launch MSRP of $282 versus $182 for the i5-8400T, and it delivers proportionally more performance in the data. The i5-8400T's lower power draw and graphics integration make it a niche pick, but for anyone comparing purely on benchmark results, the Xeon E3-1240 v5 is the definitive winner.