Intel Core i5-8400T

Intel Core i5-8400T is a 6-core, 6-thread desktop processor built on Intel's 14nm Coffee Lake architecture, with a 35W TDP and a base clock of 1700 MHz that boosts to 3.30 GHz. Its average benchmark score of 1996 places it at the 46th percentile among all CPUs, indicating a solidly mid-pack performer that trades peak throughput for efficiency. The chip supports dual-channel DDR4 memory with a 42.7 GB/s bandwidth, includes UHD Graphics 630, and launched with an MSRP of $182 in April 2018. This processor is now end-of-life, but its data reveals a clear profile: a low-power workhorse that excels in constrained environments rather than high-end compute.

Who Should Consider It

The benchmark data points to a processor designed for sustained, moderate workloads rather than burst-heavy tasks. In Cinebench R23, the multi-core score of 6297 is roughly 7x the single-core score of 889, showing that the chip scales well across all six cores when the load is parallelized. This makes the i5-8400T a reasonable fit for office productivity suites, spreadsheet crunching, and light database work where multi-threaded efficiency matters more than raw speed. The Geekbench multi-core score of 3927 reinforces this, it is more than 3.5x the single-core score of 1117, so applications that can spread work across threads will see proportionally better results.

For gaming, the picture is more nuanced. The single-core Cinebench R15 score of 89 is modest by modern standards, and many game engines still rely heavily on one or two threads. The 46th percentile ranking means that in CPU-bound scenarios, this chip will sit behind a significant portion of the market. However, the 6-core layout provides headroom for background tasks like streaming or voice chat without stealing cycles from the game thread. The UHD Graphics 630 integrated GPU means the system can run without a discrete card, but the low boost clock of 3.30 GHz will limit frame rates in demanding titles, this is a processor for esports and older games, not AAA shooters.

Content creation is a mixed bag. The Cinebench R20 multi-core score of 2644 shows that video encoding and 3D rendering tasks, which use all cores, will complete at a steady pace. Yet the single-core R20 score of 373 suggests that tasks like applying filters in photo editors or compiling code, which often bottleneck on one thread, will feel sluggish. The 9 MB shared L3 cache helps with data reuse in moderately sized working sets, but the lack of hyper-threading means only six threads are available, a limitation for heavily threaded workloads like 4K video export. For a home office PC or a quiet HTPC that occasionally renders a short clip, this chip is adequate; for a professional editing rig, it falls short.

Power and Thermals

The defining characteristic of the i5-8400T is its 35W TDP, which places it in the ultra-low-power class of desktop processors. This is a fraction of the power budget of typical desktop chips, and the benchmark results confirm that the performance ceiling is intentionally capped to stay within that envelope. The base clock of 1700 MHz is exceptionally low, which keeps idle and light-load power consumption minimal. Under sustained multi-core loads, the boost clock of 3.30 GHz represents the maximum thermal headroom the chip can sustain without exceeding its power limit.

Cooling requirements are minimal. A stock Intel cooler or any basic low-profile air cooler is sufficient, and the low TDP means that even a compact mini-ITX build with restricted airflow will not struggle to dissipate heat. The 14nm process node is mature, so thermal density is manageable at these power levels. For systems that run 24/7, such as home servers or always-on download boxes, the 35W TDP translates to low electricity draw and reduced heat output in the surrounding environment. The integrated UHD Graphics 630 also operates within this power budget, meaning a fully integrated system stays cool and quiet. There is no need for liquid cooling or high-end tower coolers; the data implies that a passive or semi-passive cooling solution could work in a well-ventilated case.

How It Compares

Intel Core i3-8350K: The i5-8400T trails the i3-8350K by a negligible 0.1% in average score (1996 vs 1997). This is statistically a tie, but the comparison is telling: the i3-8350K is a 4-core unlocked part, while the i5-8400T has 6 cores but a much lower clock. In single-threaded workloads, the i3-8350K likely wins decisively due to its higher boost, but in multi-threaded tasks, the i5-8400T's extra two cores compensate for its lower frequency. The 35W TDP versus the i3's higher power draw is the real differentiator, the i5-8400T achieves parity in average terms while drawing far less power.

Intel Core i3-10305T: The i5-8400T is 0.2% behind this newer 4-core part, with an average score of 1996 vs 2000. The i3-10305T benefits from a newer architecture, but the i5-8400T's six physical cores allow it to stay competitive in multi-threaded benchmarks. In Cinebench R23 multi-core, the i5-8400T's 6297 score shows that its core count advantage is real, yet the i3-10305T closes the gap through higher clocks per core. For users who prioritize power efficiency over raw single-thread speed, the i5-8400T remains a viable alternative.

AMD Ryzen 7 2800H: The i5-8400T is 0.3% behind this AMD mobile-derived part, scoring 1996 vs 2002. The Ryzen 7 2800H typically appears in laptops, so the comparison is unusual for a desktop chip, but the data shows near-identical average performance. The i5-8400T's advantage lies in its desktop socket and upgrade path, while the Ryzen part may have better integrated graphics. In multi-threaded workloads, the 6-core/6-thread i5-8400T matches the 4-core/8-thread Ryzen, suggesting that Intel's cores are more efficient per thread.

AMD Ryzen 7 3750H: The i5-8400T edges out this AMD part by 0.3%, with scores of 1996 vs 1989. The Ryzen 7 3750H is also a 4-core/8-thread mobile chip, so the i5-8400T's extra two physical cores give it a slight edge in average benchmarks. In single-threaded tests, the Ryzen may pull ahead due to higher boost clocks, but the i5-8400T's consistent multi-core performance keeps it ahead overall. This is a narrow victory that highlights the i5-8400T's efficiency advantage in a compact power envelope.

FAQ

Q: Is the Intel Core i5-8400T good for gaming?

A: It is adequate for light gaming, with a Cinebench R15 single-core score of 89 and a Geekbench single-core score of 1117. These figures place it in the lower half of the performance spectrum (46th percentile), so it will handle esports and older titles but will struggle with modern CPU-heavy games, especially at high frame rates.

Q: Does the i5-8400T support overclocking?

A: No, the multiplier is locked, and the base clock of 1700 MHz is fixed. The boost clock of 3.30 GHz is the maximum achievable frequency, so performance tuning is limited to adjusting power limits and cooling within the 35W TDP envelope.

Q: What memory does the i5-8400T support?

A: It supports dual-channel DDR4 memory with a maximum bandwidth of 42.7 GB/s. ECC memory is not supported, so this chip is aimed at consumer builds rather than error-correcting workstation configurations.

Q: What integrated graphics does the i5-8400T have?

A: It includes Intel UHD Graphics 630, which is sufficient for basic display output and video playback. For gaming or GPU-accelerated tasks, a discrete graphics card is recommended, as the integrated solution relies on the modest 3.30 GHz boost clock for any compute.

Q: How does the i5-8400T compare to the Ryzen 7 3750H?

A: The i5-8400T scores 1996 on average, which is 0.3% higher than the Ryzen 7 3750H's 1989. The Intel chip has 6 cores versus the AMD's 4 cores, which helps in multi-threaded workloads, but the Ryzen may have better single-core performance in certain scenarios.

Q: Is the i5-8400T still worth buying in the current market?

A: The processor is end-of-life and was released in April 2018. Its 46th percentile ranking and average score of 1996 mean it is outclassed by modern budget chips, but for a low-power, 35W TDP system where silence and efficiency are priorities, it remains functional.

Single-Thread vs Multi-Thread Behavior

The i5-8400T demonstrates a pronounced split between single-thread and multi-thread performance. In Cinebench R23, the multi-core score of 6297 is 7.1x the single-core score of 889, which is a wider ratio than typical for 6-core chips. This indicates that the processor's 1700 MHz base clock severely limits single-thread throughput, while the boost clock of 3.30 GHz is only achievable when a single core is active, and that boost is not sustained across all cores. In Geekbench, the multi-core score of 3927 is 3.5x the single-core score of 1117, showing a similar but less extreme scaling factor.

For real workloads, this means the i5-8400T behaves like two different processors depending on the task. In single-threaded applications, such as web browsing, word processing, or older games, the chip feels sluggish, with the low base clock dominating performance. The single-core Cinebench R15 score of 89 is particularly telling; it is roughly half of what a modern high-end desktop chip would achieve. Conversely, in multi-threaded workloads like video encoding, 3D rendering, or batch file processing, the six cores engage fully, and the 6297 Cinebench R23 score shows that the chip can hold its own against newer 4-core parts. The 9 MB shared L3 cache helps mitigate the low clock speed by reducing memory latency, but it cannot overcome the fundamental frequency deficit.

The practical implication is that users should avoid single-thread-bound tasks on this chip. Compiling code, applying complex filters in image editors, or running a single-threaded physics simulation will all feel slow. However, tasks that can be parallelized, such as rendering a video with multiple frames in flight or running a multi-threaded benchmark, will see the processor punch above its weight class. The 35W TDP is the root cause: to stay within that power budget, Intel capped the base clock dramatically, and the boost clock is only a temporary measure. This makes the i5-8400T a specialist for efficiency-focused multi-threaded workloads, not a general-purpose performer.