Intel Core i5-8400 Desktop Processor: features, specs and what it fits

The Intel Core i5-8400 is an 8th Generation desktop processor with six cores. It has built-in graphics and plugs into Intel 300 Series motherboards, so it works for a general-purpose desktop without a separate graphics card. It is an older generation, which makes the compatibility details below the most important thing to understand.

Cores, clock speed and cache

Intel lists six cores, a base frequency of 2.80 GHz and a maximum Turbo frequency of 4.00 GHz, with 9 MB of cache. The base figure is the speed the processor is designed to hold under sustained load. Turbo is a short-term boost that applies when thermal and power conditions allow, so real-world clocks move between the two.

The description notes that the 8th Gen family added two cores compared with the previous generation. More cores typically help with multitasking and with software that spreads work across several threads, such as video editing, compiling code or running many applications together. Check Intel's specification sheet for the thread count, as the listing text gives inconsistent figures.

Integrated graphics

The processor includes Intel UHD Graphics 630. Integrated graphics handle everyday work: web browsing, office applications, high-resolution video playback and light games. They remove the need for a separate graphics card in a basic build. For demanding games or 3D work, a dedicated card is typically added. To use the integrated graphics, your motherboard needs a video output.

Memory support

The description says the processor supports two-channel DDR4 memory, with up to 64 GB and transfer speeds up to 2666 MT/s. Running two matched memory modules typically takes advantage of the dual-channel design.

Optane support

The listing says the processor supports Intel Optane Memory. Intel describes this as an accelerator paired with a 2.5-inch hard drive to speed up a system. It was mainly meant for systems that still boot from a hard drive. Check whether your motherboard supports it.

Compatibility with Intel 300 Series boards

Intel states the processor works only with motherboards based on Intel 300 Series chipsets. It will not work in boards made for older or newer processor generations, even if the socket looks similar. Check your board's supported-CPU list, since some boards need a BIOS update before they will recognise a given processor.

The box is a boxed retail package, and the listed dimensions are 4.6 x 2.8 x 4.0 inches with a weight of 0.7 lb. A cooler is usually included with processors of this type, but check the contents list for this model.

Who it suits

It suits someone building or upgrading an Intel 300 Series desktop for everyday computing, home office work or media use, or someone replacing a processor in an existing system on that platform.

What to check before you buy

• Chipset: confirm your motherboard uses an Intel 300 Series chipset.
• BIOS: check whether your board needs a BIOS update for this processor.
• Memory: match DDR4 modules to what the board supports.
• Cooling: confirm what cooler is included and that it fits your case.
• Display output: make sure your board has video outputs if you rely on integrated graphics.

The short version

• A six-core 8th Gen Intel desktop processor, 2.80 GHz base and up to 4.00 GHz Turbo.
• 9 MB cache and Intel UHD Graphics 630.
• Dual-channel DDR4 support, up to 64 GB.
• Works only with Intel 300 Series chipset motherboards.
• Supports Intel Optane Memory.

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