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Intel 8th Gen Core i5-8400 Processor
Intel

Intel 8th Gen Core i5-8400 Processor

Bottom line: The Intel 8th Gen Core i5-8400 Processor: 6 physical cores, two more than the prior-gen mainstream Core i5; main trade-off: locked in practice: 2.80 GHz base limits headroom vs K-series.

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By , Founder & Editor-in-Chief · Listing data updated

Mike Perry — Hardware researcher since 2014. For retro PC hardware and period-correct parts, synthesises manufacturer documentation, community compatibility lists and marketplace listings rather than first-hand lab testing. Core beat: GPU performance across gaming, rendering, and local-LLM inference.

Pros & Cons

Pros

  • ✓ 6 physical cores, two more than the prior-gen mainstream Core i5
  • ✓ Turbos to 4.00 GHz from a 2.80 GHz base
  • ✓ 9 MB cache supports multi-app and streaming loads
  • ✓ Intel UHD Graphics 630 built in, no GPU needed to boot

Cons

  • ✗ Locked in practice: 2.80 GHz base limits headroom vs K-series
  • ✗ Intel 300 Series motherboards only, no 100/200 Series reuse
  • ✗ 6 threads on 6 cores; no Hyper-Threading for heavy render work
  • ✗ UHD Graphics 630 is display-class, not for modern gaming

Manufacturer description

The Intel Core i5-8400 is the six-core Coffee Lake chip that redefined mainstream desktop performance, adding two cores over the previous generation without asking you to move to an enthusiast platform. It runs a 2.80 GHz base clock and climbs to a 4.00 GHz max turbo frequency, backed by 9 MB of cache, so single-threaded work stays quick while six physical cores handle streaming, light editing, and multi-app workloads that used to choke quad-core builds. Integrated Intel UHD Graphics 630 drives displays and media playback without a discrete card, which makes this Core i5 a practical base for…

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SpecPicks Verdict

SpecPicks scored Intel 8th Gen Core i5-8400 Processor using a rating × review-volume × price-fit model applied to published specs and reviews across the retro cpus category. Intel's retro cpus lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.

Common buyer scenarios for retro cpus of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.

Frequently Asked Questions

What motherboard do I need for the i5-8400?

A motherboard based on an Intel 300 Series chipset, such as B360, H310, H370 or Z370. Intel lists the i5-8400 as compatible only with 300 Series boards, so older 100 and 200 Series LGA 1151 boards will not run it even though the socket looks identical.

Does the i5-8400 have integrated graphics?

Yes. It includes Intel UHD Graphics 630, so you can build and boot the system, run displays, and handle media playback without buying a discrete graphics card. Add a GPU later if you want serious gaming performance.

How many cores and threads does it have?

Six cores. Intel's feature list cites 6 cores and 12 threads for this SKU, while the product description states 6 cores and 6 threads. Confirm the threading spec on the current product listing before buying if Hyper-Threading matters to your workload.

What clock speeds does the i5-8400 run at?

It runs a 2.80 GHz base clock and reaches up to 4.00 GHz max turbo frequency, with 9 MB of cache. Sustained turbo depends on your cooler and motherboard power settings.

Is the i5-8400 worth buying at this point?

Six cores at up to 4.00 GHz still cover browsing, office work, emulation, and light content creation. It suits a budget or secondary build rather than a high-refresh gaming rig.

Key Features

  • Intel UHD Graphics 630
  • Compatible only with Motherboards based on Intel 300 Series Chipsets
  • 6 Cores / 12 Threads
  • 2.80 GHz up to 4.00 GHz Max Turbo Frequency / 9 MB Cache
  • Intel Optane Memory Supported

Full Specifications

BrandIntel
TurboYes
Wattage65
PlatformWindows
CPU ModelCore i5
CPU Speed2.8 GHz
CPU SocketLGA 1151
Model NumberBX80684I58400
Built-In Media1 processor
Item Type Name8th Gen Intel® Core™ i5-8400 Processor
Mfr Part NumberBX80684I58400
Number of Items1
Processor BrandIntel
Processor Count6
Processor Speed2.8 GHz
Secondary Cache9 MB
CPU ManufacturerIntel
Processor SeriesCore i5
Processor SocketLGA 1151
Processor Core Count1

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