Quick Verdict
A modest refresh of the 8400T, offering slightly higher clocks in the same 35W envelope, primarily for OEM systems.
Overview
Launch
2018
Status
End-of-lifeGeneration
8th Generation (Coffee Lake)
Market
Desktop
The Intel Core i5-8420T is a low-power desktop processor part of the 8th generation Coffee Lake family. Released in September 2018, it is a slight revision of the i5-8400T. Built on the 14nm process, it features 6 cores and 6 threads. The 'T' suffix indicates a 35W TDP, making it suitable for small form factor and energy-efficient systems. The base clock is 1.8 GHz, with a maximum turbo boost of 3.4 GHz, offering a minor bump over its predecessor. It includes 9 MB of Intel Smart Cache and supports dual-channel DDR4 memory up to 2666 MT/s. The integrated Intel UHD Graphics 630 handles standard display output. With 16 PCIe 3.0 lanes, it provides sufficient bandwidth for typical desktop expansions. Compatible with LGA 1151 sockets on 300-series chipsets, the i5-8420T is an OEM-focused chip designed for corporate environments and compact PCs where power efficiency is paramount.
The Intel Core i5-8420T is an 8th Gen Coffee Lake processor designed for low-power desktops. With 6 cores and 6 threads, it handles standard office tasks well. The 'T' means 35W TDP for quiet operation.
It has a base clock of 1.8 GHz and boosts to 3.4 GHz.
It supports DDR4-2666 and includes UHD Graphics 630. It is an OEM-focused chip, rarely found in retail, offering a slight bump over the 8400T.
Specifications
Performance
6 cores provide good office performance, but single-core is limited.
Suitable for basic VMs, but lacks threads.
Marginally better than 8400T, but still too slow for modern gaming.
Excellent 35W efficiency.
- •Low clocks limit high-refresh gaming.
- •Integrated graphics are weak.
- •Needs a discrete GPU for any real gaming.
- •No dedicated AI hardware.
- •Slow CPU inference.
Architecture
14nm
Process Node
Coffee Lake
Codename
6C / 6T
Core Config
9 MB
L3 Cache
35 W
TDP
Architecture Overview
The Core i5-8420T utilizes the Coffee Lake architecture, a 14nm design that brought 6-core configurations to the mainstream desktop market. It is a slightly binned version of the 8400T, optimized for OEM deployments.
CPU Design
Featuring 6 physical cores and 6 threads, it uses a ring bus architecture to connect to the 9 MB L3 Smart Cache. The lack of Hyper-Threading keeps power consumption low while maintaining parallel processing capability.
Memory Subsystem
The integrated memory controller supports dual-channel DDR4 memory up to 2666 MT/s. This provides adequate bandwidth for integrated graphics and everyday computing tasks.
PCIe & I/O
It provides 16 PCIe 3.0 lanes for expansion. This is sufficient for a discrete GPU or a fast NVMe drive, though the 35W TDP usually precludes high-end GPUs.
Overclocking
The processor is locked, preventing manual multiplier adjustment. Its 35W TDP is strictly enforced, ensuring it remains within the thermal limits of small OEM coolers, making it highly reliable for office environments.
- 100 MHz higher base clock
- 100 MHz higher max turbo
- Refined binning for OEMs
Key Highlights
- Low 35W TDP
- 6 cores for multi-tasking
- Runs cool and quiet
- Good for basic office use
- Very similar to 8400T
- Locked multiplier
- No Hyper-Threading
- Hard to find retail, OEM only
History
The Core i5-8420T was released in September 2018 as a minor refresh to the Coffee Lake-T lineup.</br>Intel frequently releases these 'x20' SKUs to provide OEMs with slightly updated specs for marketing purposes or to fulfill specific contract requirements.</br>The 8420T offered a negligible 100 MHz bump over the 8400T, barely noticeable in real-world use.
</br>It was primarily deployed in corporate desktop machines and all-in-one PCs where the 35W TDP was crucial for thermal management.</br>This chip highlights Intel's strategy of maximizing silicon yield by creating numerous slightly different SKUs from the same die.</br>While irrelevant to custom builders, it served its purpose in the OEM space efficiently.
Improvements over Previous Generation
- 100 MHz higher base clock
- 100 MHz higher max turbo
- Refined binning for OEMs
Alternatives & Competitors
Should You Buy It?
Not Recommended for the right buyer
Finding a cheap used OEM PC with this chip for basic office work.
Avoid if…
- Building a custom PC
- You need high performance
- You want an upgrade path
Use Cases
Interesting Facts
It is essentially an i5-8400T with a 100 MHz clock bump.
It was launched in September 2018.
It is an OEM part, rarely sold in retail boxes.
It has a 35W TDP.
It uses the LGA 1151 socket.
It supports DDR4-2666 memory.
The processor includes Intel UHD Graphics 630.
It features 6 cores but only 6 threads.
It was designed for corporate desktop environments.
The max turbo boost is 3.4 GHz.
People Also Ask
What is the difference between i5-8400T and i5-8420T?
The 8420T has 100 MHz higher base and boost clocks.
Is Intel Core i5-8420T good for gaming?
No, it is too weak for modern gaming.
What is the TDP of the i5-8420T?
35 Watts.
Can I overclock the i5-8420T?
No, it is locked.
How many cores does the i5-8420T have?
6 cores and 6 threads.
What socket does it use?
LGA 1151.
Does it have integrated graphics?
Yes, Intel UHD Graphics 630.
Is the i5-8420T an OEM part?
Yes, it is mostly found in pre-built PCs.
What RAM does it support?
DDR4 up to 2666 MT/s.
Can it run Windows 11?
Yes, it is supported.
Frequently Asked Questions
Is the Core i5-8420T still good in 2024?
It is okay for basic office tasks, but outdated.
Does it come with a cooler?
OEM systems usually include a cooler.
What is the max turbo?
Up to 3.4 GHz.
What chipset does it need?
Intel 300-series chipset.
Is it good for video editing?
It can handle basic 1080p editing, but slowly.
What is the base clock?
1.8 GHz.
Is it good for a home server?
Yes, its 35W TDP is great for servers.
Does it support Hyper-Threading?
No, it has 6 threads on 6 cores.
Can I use it for streaming?
No, it is too slow for that.
What is the max memory?
Up to 128 GB.