Quick Verdict
An 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.
Overview
Launch
Sep 1st, 2018
Status
End-of-lifeGeneration
Core i5 (Coffee Lake Refresh)
Market
Desktop
The Intel Core i5-9400T is a low-power, six-core desktop processor introduced as part of the Coffee Lake Refresh lineup, designed specifically for small form factor (SFF) systems and mini PCs where thermal constraints are strict.
Designed for mini PCs and AIO systems, the Core i5-9400T operates within a strict 35W TDP. It features 6 cores and 6 threads, clocking up to 3.4 GHz, providing adequate performance for everyday computing and multitasking without requiring aggressive cooling solutions.
Specifications
Performance
Handles office applications, large spreadsheets, and multitasking without issues.
Can run basic VMs, but lacks Hyper-Threading for heavy parallel workloads.
Capable of light eSports gaming using integrated graphics, but not suited for AAA titles.
Outstanding power-to-performance ratio for low-power segments.
- •UHD 630 handles older or lightweight games well
- •Pairs best with discrete GPUs for 1080p gaming
- •Not ideal for high-refresh-rate AAA gaming
- •No dedicated AI hardware
- •Low core clocks limit CPU-based inference
Architecture
14 nm
Process Node
Coffee Lake
Codename
6C / 6T
Core Config
9 MB
L3 Cache
35 W
TDP
Architecture Overview
Built on Intel's highly refined 14-nanometer lithography, the Core i5-9400T utilizes the Coffee Lake microarchitecture. This design represents a continuous optimization of the Skylake lineage, focusing on maximizing core density within mainstream power limits. The processor features 6 physical cores configured without Hyper-Threading, adhering to Intel's tier segmentation of the time. A ring bus architecture facilitates low-latency communication between the cores, the 9 MB SmartCache L3 memory, and the integrated graphics. The built-in UHD Graphics 630 features 24 execution units and supports hardware acceleration for modern video codecs like HEVC. Memory support is officially rated for dual-channel DDR4-2666, ensuring adequate bandwidth for system responsiveness. The chip communicates with the motherboard via the FC-LGA1151 package, providing 16 PCIe 3.0 lanes for discrete components. Despite its low TDP, Intel retained comprehensive security and instruction set support, including AES-NI, AVX2, and VT-x, ensuring capable virtualization and cryptographic performance.
CPU Design
6 physical cores without Hyper-Threading.
Memory Subsystem
Dual-channel DDR4-2666.
PCIe & I/O
16 PCIe 3.0 lanes directly from the CPU.
Overclocking
Locked multiplier.
- Higher max turbo frequency
- Improved clock-for-clock efficiency
Key Highlights
- Extremely low 35W TDP
- 6 physical cores for multitasking
- Integrated UHD Graphics 630
- Runs exceptionally cool
- Quiet operation potential
- Low base clock of 1.8 GHz
- No Hyper-Threading
- Locked multiplier
- End-of-life platform
- Limited upgrade path
History
The Core i5-9400T was launched on September 1st, 2018, coinciding with the broader rollout of Intel's 9th Generation Core processors. This release was a critical period for Intel, as the company faced intense pressure from AMD's resurgent Ryzen architecture. By introducing the Coffee Lake Refresh, Intel aimed to solidify its mainstream dominance by permanently increasing core counts across the board; the i5 tier transitioned from 4 cores to 6 cores, a significant leap for budget and mid-range builders.
The 'T' suffix denoted Intel's continued commitment to power-optimized parts for system integrators building compact desktops. While enthusiasts largely focused on the 'K' series unlocked chips, the 9400T quietly found its way into millions of office machines, NUCs (Next Unit of Computing), and all-in-one systems. Its launch marked a turning point where even low-power enterprise and SFF systems could benefit from hexa-core processing, effectively killing off the quad-core era for standard desktop computing tasks and raising the baseline for system responsiveness.
Improvements over Previous Generation
- Higher max turbo frequency
- Improved clock-for-clock efficiency
Alternatives & Competitors
Should You Buy It?
Recommended for the right buyer
Building or upgrading a low-power, small form factor system where a 35W TDP is strictly required.
Avoid if…
- Building a standard ATX desktop
- Prioritizing raw gaming performance
- Doing heavy multi-threaded content creation
Use Cases
Interesting Facts
The 'T' suffix officially designates a low-power Intel desktop processor.
It shares the same physical silicon as the 65W i5-9400 but is binned for efficiency.
Includes Intel UHD Graphics 630 capable of driving three 4K displays.
Officially supports DDR4-2666 memory speeds.
Released simultaneously with other 9th Gen Coffee Lake Refresh chips in late 2018.
Uses the FC-LGA1151 package, requiring a 300-series chipset motherboard.
Maximum turbo boost is 3.4 GHz, achieved only under thermal headroom.
Lacks TSX (Transactional Synchronization Extensions) support despite being listed in some early ARK specs.
Part number SR3X8 is specific to this low-power variant.
Can operate entirely passively cooled with a sufficiently large heatsink.
People Also Ask
Is the Intel Core i5-9400T good for gaming?
It is only suitable for light or older games using the integrated UHD 630. For serious gaming, a dedicated GPU is required.
Can you overclock the i5-9400T?
No, the processor features a locked multiplier and does not support overclocking.
What is the TDP of the Core i5-9400T?
It has a default TDP of 35 Watts, making it ideal for small form factor builds.
Does the i5-9400T have integrated graphics?
Yes, it includes the Intel UHD Graphics 630.
What socket does the i5-9400T use?
It uses the Intel Socket 1151 (FC-LGA1151 package).
How many cores and threads does the i5-9400T have?
It features 6 cores and 6 threads. It does not support Hyper-Threading.
What RAM speed is supported by the i5-9400T?
It officially supports dual-channel DDR4 memory at 2666 MT/s.
What is the maximum turbo frequency of the i5-9400T?
The maximum Intel Turbo Boost frequency is 3.4 GHz.
Is the i5-9400T good for a home server?
Yes, its low 35W TDP makes it excellent for always-on home servers and NAS devices.
Does the i5-9400T support Windows 11?
Officially it is not supported by Windows 11, but it can run via workarounds.
Frequently Asked Questions
Does the Core i5-9400T come with a cooler?
Tray versions do not. Boxed versions typically include a low-profile stock cooler.
What is the difference between the i5-9400 and i5-9400T?
The i5-9400 has a 65W TDP and higher clocks (2.9 GHz base), while the i5-9400T has a 35W TDP and a 1.8 GHz base clock.
Can the i5-9400T run Adobe Premiere Pro?
Yes, but performance will be limited due to the low base clock. It is best for basic 1080p editing.
What PCIe version does the i5-9400T support?
It supports PCIe 3.0 with 16 lanes directly from the CPU.
Does the i5-9400T support ECC memory?
No, the Core i5-9400T does not support Error-Correcting Code (ECC) memory.
What motherboards are compatible with the i5-9400T?
It is compatible with Intel 300-series chipset motherboards (Z390, B360, H310, etc.) with the LGA 1151 socket.
What is the L3 cache size of the i5-9400T?
It has a 9 MB shared L3 SmartCache.
Does the i5-9400T support Hyper-Threading?
No, it has 6 physical cores but processes only 6 threads simultaneously.
Is the i5-9400T unlocked?
No, it has a locked multiplier and cannot be overclocked.
What is the base clock speed of the i5-9400T?
The base clock speed is 1.8 GHz.