I5 8400

Overview

The Intel Core i5-8400 is a 8th‑Generation Coffee Lake desktop processor with 6 physical cores and 6 threads, a base clock of 2.8GHz and Turbo Boost up to 4.0GHz. It carries 9MB of Intel Smart Cache, a 65W TDP and uses the LGA1151 socket paired with 300‑series motherboards (Z370, B360, H370).

Architecture and real-world performance

Built on Intel's Coffee Lake 14nm++ process, the i5-8400 delivers strong single‑core performance and improved multi‑core responsiveness compared with earlier 6th/7th gen Core i5 parts thanks to its six full cores (this model does not have Hyper‑Threading so it runs 6 threads). Typical behaviour is very good for gaming and day‑to‑day apps — single‑threaded boost to 4.0GHz gives snappy frame times and quick app launches. It pairs with dual‑channel DDR4‑2666 memory (official support up to 64GB) and includes Intel UHD Graphics 630 for basic display and media tasks, including Quick Sync hardware video acceleration.

Practical use cases

The i5-8400 is ideal for 1080p gaming when combined with a discrete GPU — it won't bottleneck most mid‑range cards and provides smooth high‑FPS play in esports and many AAA titles at medium–high settings. For content creators it's a solid entry point: good responsiveness for photo editing and fast turnaround on timeline scrubbing; it can handle 4K editing workflows, but long 4K renders and heavy multi‑threaded exports will benefit from CPUs with more cores/threads. It’s also excellent for office work, web browsing, light streaming and HTPC builds thanks to the modest 65W power draw and integrated UHD 630 for video decode/encode offload.

Specs summary

• Model: Intel Core i5-8400 (8th Gen, Coffee Lake)
• Cores / Threads: 6 cores / 6 threads (no Hyper‑Threading)
• Base / Turbo: 2.8GHz base, up to 4.0GHz Turbo Boost
• Cache: 9MB Intel Smart Cache
• TDP: 65W
• Integrated GPU: Intel UHD Graphics 630 (Quick Sync support)
• Memory Support: Dual‑channel DDR4‑2666 (up to 64GB practical limit)
• Socket / Chipset: LGA1151 (300‑series motherboards such as Z370/B360/H370)
• Unlocked? No — non‑K part, multiplier locked (no CPU overclocking)

Who this processor is best suited for

The i5-8400 is best for mainstream gamers on a budget, office and home‑office users, HTPC builders and creative hobbyists who need solid single‑threaded speed and good 1080p gaming performance without the expense of higher‑core CPUs; it’s a practical choice when you want efficient everyday performance rather than extreme multi‑threaded workstation power.