CPU Comparison
Intel Core i5-8420T vs Intel Core i5-9400T
A side-by-side comparison of specs, performance and value. 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 Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
6 cores provide good office performance, but single-core is limited.
Handles office applications, large spreadsheets, and multitasking without issues.
Gaming
Marginally better than 8400T, but still too slow for modern gaming.
Capable of light eSports gaming using integrated graphics, but not suited for AAA titles.
Virtualization
Suitable for basic VMs, but lacks threads.
Can run basic VMs, but lacks Hyper-Threading for heavy parallel workloads.
Efficiency
Excellent 35W efficiency.
Outstanding power-to-performance ratio for low-power segments.
Specialized Performance
AI / ML
- No dedicated AI hardware.
- Slow CPU inference.
- No dedicated AI hardware
- Low core clocks limit CPU-based inference
Content Creation
Gaming
- Low clocks limit high-refresh gaming.
- Integrated graphics are weak.
- Needs a discrete GPU for any real gaming.
- UHD 630 handles older or lightweight games well
- Pairs best with discrete GPUs for 1080p gaming
- Not ideal for high-refresh-rate AAA gaming
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- Low 35W TDP
- 6 cores for multi-tasking
- Runs cool and quiet
- Good for basic office use
Cons
- Very similar to 8400T
- Locked multiplier
- No Hyper-Threading
- Hard to find retail, OEM only
Pros
- Extremely low 35W TDP
- 6 physical cores for multitasking
- Integrated UHD Graphics 630
- Runs exceptionally cool
- Quiet operation potential
Cons
- Low base clock of 1.8 GHz
- No Hyper-Threading
- Locked multiplier
- End-of-life platform
- Limited upgrade path
Competitors & Alternatives
Intel Core i5-8420T
- Compare head-to-headIntel Core i5-8400TRival
Low Power Desktop
- AMD Ryzen 5 2400GERival
Low Power Desktop
- Compare head-to-headIntel Core i5-8500TRival
Low Power Desktop
- AMD Ryzen 3 2200GERival
Budget Low Power
- Compare head-to-headIntel Core i3-8100TRival
Budget Low Power
- AMD Ryzen 5 3400GEAlt
Better integrated graphics.
Modern alternative with much better IPC.
Compare head-to-head- AMD Ryzen 5 5600GEAlt
Better efficiency and multi-core.
Intel Core i5-9400T
- AMD Ryzen 5 2600ERival
Low Power Desktop
- AMD Ryzen 5 3400GERival
Low Power Desktop
- Compare head-to-headIntel Core i5-8500TRival
Low Power Desktop
- Compare head-to-headIntel Core i7-8700TRival
Low Power Desktop
- AMD Ryzen 3 3200GERival
Low Power Desktop
Better raw performance if power constraints are not a strict issue.
Compare head-to-headSlightly higher clocks within the same 35W envelope.
Compare head-to-head- Intel Core i3-9100Alt
Cheaper alternative for basic office needs.
- AMD Ryzen 5 3400GAlt
Significantly better integrated graphics performance.
- Intel Core i5-10400TAlt
Newer generation with Hyper-Threading support.
Our Verdict on Each
A modest refresh of the 8400T, offering slightly higher clocks in the same 35W envelope, primarily for OEM systems.
Best for: Finding a cheap used OEM PC with this chip for basic office work.
Read the full reviewAn efficient 6-core chip that trades raw clock speed for a strict 35W thermal envelope, making it perfect for compact systems but less ideal for heavy workloads.
Best for: Building or upgrading a low-power, small form factor system where a 35W TDP is strictly required.
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i5-8420T or Intel Core i5-9400T?
Based on our editorial ratings, the Intel Core i5-9400T comes out ahead with a score of 7.5/10. That said, the best choice depends on your workload — check the spec and performance breakdown above for gaming, productivity and efficiency differences.
Which is faster for gaming, Intel Core i5-8420T or Intel Core i5-9400T?
For gaming, the Intel Core i5-9400T leads with a gaming performance score of 55/100 among Intel Core i5-8420T and Intel Core i5-9400T.
Do Intel Core i5-8420T and Intel Core i5-9400T use the same socket?
No. They use different sockets (Intel Core i5-8420T: LGA 1151, Intel Core i5-9400T: Intel Socket 1151), so each needs a compatible motherboard.
Which is faster in multi-core benchmarks?
The Intel Core i5-8420T posts the highest multi-core benchmark score. Multi-core results: Intel Core i5-8420T (8,600). Benchmark figures are approximate and workload-dependent.