Intel Core i5-8400

The Intel Core i5-8400 is a 6-core, 6-thread desktop processor built on the 14 nm Coffee Lake architecture, with a base clock of 2.80 GHz and a boost clock of 4.00 GHz. It pairs with a 65 W TDP, dual-channel DDR4 memory support, and integrated UHD Graphics 630, all in the Intel Socket 1151 form factor. Launched on October 4, 2017, this part is now end-of-life, with a launch MSRP of $182. Its average benchmark score of 13,888 places it in the 73rd percentile of all CPUs tracked.

Benchmark Performance

The i5-8400’s average benchmark score of 13,888 puts it in a tight cluster of competitors. Against its nearest rivals, the data shows a margin of less than 2% in every direction. It sits 0.2% ahead of the Intel Core i7-8750H (13,857), 0.9% ahead of the AMD Ryzen 5 5500U (13,770), and 0.3% behind the AMD EPYC 7443 (13,936). The largest gap is to the AMD EPYC 7552, which leads by 1.6% (14,115). These deltas are small enough that real-world application differences would be negligible in most workloads.

In Cinebench R23, the i5-8400 scores 7,842 points in multi-core and 1,107 in single-core. The R20 run yields 3,293 multi-core and 464 single-core, while the older R15 test produces 790 and 111, respectively. These figures indicate a balanced part that is clearly capable in lightly threaded tasks but does not excel in heavily parallel rendering. The Passmark suite reinforces this: a multi-thread score of 9,225 and a single-thread score of 2,371, with integer math at 25,573 and floating-point math at 22,006. Data compression (129,951) and encryption (2,824) show moderate throughput, while extended instructions (11,543) and random string sorting (15,952) round out the picture. The physics test (635) and prime-number search (37) are lower, reflecting the absence of hyper-threading.

The percentile placement at 73 means the i5-8400 outperforms roughly three-quarters of all CPUs in the database, yet it is not a top-tier part. Its average score is within 0.2% of the i7-8750H, a mobile processor that shares the same core count but different power characteristics. The closeness of these scores suggests that for many applications, the i5-8400 and i7-8750H are effectively interchangeable, despite their different market segments.

Power and Thermals

The i5-8400 is rated at a 65 W TDP, which is modest for a 6-core desktop chip on the 14 nm process. This power envelope allows it to be cooled by a stock cooler or a capable air cooler without difficulty. The base clock of 2.80 GHz and boost of 4.00 GHz are not extreme, and the locked multiplier means no overclocking headroom. As a result, thermal management is straightforward: a standard tower-style air cooler is more than sufficient for sustained loads. The die size of 154 mm² and the shared 9 MB L3 cache contribute to a compact package that does not demand exotic cooling solutions. The 65 W rating also places it in the same power class as many 6-core parts from the same era, making it a sensible choice for mainstream desktop builds where power draw is a consideration.

Single-Thread vs Multi-Thread Behavior

The i5-8400’s single-thread performance is solid for its generation. In Cinebench R23, it achieves 1,107 points, while the multi-core score of 7,842 indicates that scaling to six cores yields a substantial increase, but not a linear one. The lack of hyper-threading means that the six threads operate independently, and workloads that benefit from more than six threads will see limited gains. The Passmark single-thread score of 2,371 versus a multi-thread score of 9,225 shows a ratio of roughly 3.9 to 1, which is typical for a 6-core/6-thread part. In everyday tasks such as web browsing, office productivity, and light content creation, the single-thread performance will dominate, and the i5-8400 performs admirably there. For video editing or 3D rendering that can use many threads, the CPU will still deliver respectable results, but it will lag behind parts with more threads or higher multi-core scaling.

The split between single-thread and multi-thread scores suggests a balanced design. The boost clock of 4.00 GHz provides strong per-core performance, while the six physical cores handle parallel workloads adequately. The R15 single-core score of 111 and multi-core of 790 show a similar pattern. This behavior makes the i5-8400 well-suited for gamers and general users who need responsive single-threaded performance, while still offering enough multi-threaded capability for occasional productivity tasks.

FAQ

Q: What is the TDP of the Intel Core i5-8400?

A: The TDP is rated at 65 W.

Q: Does the i5-8400 have integrated graphics?

A: Yes, it includes UHD Graphics 630.

Q: What memory type does it support?

A: It supports dual-channel DDR4 memory, with a bandwidth of 42.7 GB/s.

Q: Is the multiplier unlocked for overclocking?

A: No, the multiplier is locked.

Q: What socket does the i5-8400 use?

A: It uses Intel Socket 1151.

Q: When was the i5-8400 released?

A: It was released on October 4, 2017.

Q: What is the L3 cache size?

A: It has 9 MB of shared L3 cache.

How It Compares

Intel Core i7-8750H – The i5-8400 is 0.2% ahead in average benchmark score (13,888 vs. 13,857). This is a negligible margin, and the two parts are effectively performance peers in aggregate. The i7-8750H is a mobile processor, but the data shows no meaningful difference in average throughput.

AMD EPYC 7443 – The EPYC 7443 leads the i5-8400 by 0.3% (13,936 vs. 13,888). Despite being a server-class chip, the average score is nearly identical, highlighting the i5-8400’s competitive position in single-thread and lightly threaded workloads. The EPYC’s advantage is minimal and unlikely to be noticeable outside highly parallel server tasks.

AMD Ryzen 5 5500U – The i5-8400 is 0.9% faster than the Ryzen 5 5500U (13,888 vs. 13,770). This is the largest positive delta among the rivals, but still under 1%. The Ryzen 5 5500U is a mobile part with lower power draw, yet the i5-8400 manages to edge it out in average score.

AMD EPYC 7552 – The EPYC 7552 is 1.6% ahead of the i5-8400 (14,115 vs. 13,888). This is the biggest performance gap in the rival set, but still modest. The EPYC 7552 is a high-core-count server processor, so its lead in average score is expected; the i5-8400 remains competitive in single-threaded tasks but falls behind in multi-threaded throughput.