
Core i5-6400T vs Core i3-8140U

Core i5-6400T

Core i3-8140U
Performance Spectrum - CPU
About PassMark
PassMark CPU Mark evaluates processor speed through complex mathematical computations. It provides a reliable metric to compare multi-core performance, where higher scores indicate faster processing for multitasking, gaming, and heavy workloads.
Value Upgrade Path
This is the official ChipVERSUS Value Rating, comparing raw performance (PassMark) per dollar. Components placed above yours deliver better value for money. The Core i5-6400T is positioned at rank 747 and the Core i3-8140U is on rank 530, so the Core i3-8140U offers better cost-efficiency for playing games.
Avg price is the current average price collected from markets across the web.
Performance Per Dollar Core i5-6400T
Performance Per Dollar Core i3-8140U
Performance Comparison
About PassMark🏆 Chipversus Verdict
🚀 Performance Leadership
| Insight | Core i5-6400T | Core i3-8140U |
|---|---|---|
| Gaming | ❌ Lower gaming performance | ✅ Superior gaming performance |
| Workstation | ✅ Better multi-core power | ❌ Weaker in multi-core tasks |
| Price | ⚠️ Higher cost ($40) | ✅ More affordable ($0) |
| Longevity | 🛑 Legacy (Skylake (2015−2016) / 14 nm) | ✨ Modern (Legacy / 14 nm) |
💎 Value Proposition
| Insight | Core i5-6400T | Core i3-8140U |
|---|---|---|
| Cost Efficiency | ❌ Lower cost efficiency | ❌ Lower cost efficiency |
| Upfront Cost | ⚠️ Higher cost ($40) | ✅ More affordable ($0) |
Performance Check
To accurately isolate CPU performance, all benchmarks below use an NVIDIA RTX 4090 as the reference GPU. This eliminates GPU-side bottlenecks and highlights pure processing throughput differences between the CPUs.
Note: Real-world results may vary based on your actual GPU. CPU performance impact is more visible in processing-intensive titles and high-refresh-rate gaming scenarios.
Technical Specifications
Side-by-side comparison of Core i5-6400T and Core i3-8140U

Core i5-6400T
The Core i5-6400T is manufactured by Intel. It was released in 1 September 2015 (10 years ago). It is based on the Skylake (2015−2016) architecture. It features 4 cores and 4 threads. Base frequency is 2.2 GHz, with boost up to 2.8 GHz. L3 cache: 6 MB. L2 cache: 1 MB. Built on 14 nm process technology. Socket: LGA1151. Thermal design power (TDP): 35 Watt. Memory support: DDR3, DDR4. Passmark benchmark score: 4,243 points. Launch price was $192.

Core i3-8140U
The Core i3-8140U is manufactured by Intel. It was released in 1 October 2019 (6 years ago). It features 2 cores and 4 threads. Base frequency is 2.1 GHz, with boost up to 3.9 GHz. L3 cache: 4 MB Intel® Smart Cache. Built on 14 nm process technology. Socket: FCBGA1528. Thermal design power (TDP): 15 Watt. Memory support: DDR4-2400, LPDDR3-2133. Passmark benchmark score: 4,227 points. Launch price was $69.
Processing Power
The Core i5-6400T packs 4 cores / 4 threads, while the Core i3-8140U offers 2 cores / 4 threads — the Core i5-6400T has 2 more cores. Boost clocks reach 2.8 GHz on the Core i5-6400T versus 3.9 GHz on the Core i3-8140U — a 32.8% clock advantage for the Core i3-8140U (base: 2.2 GHz vs 2.1 GHz). The Core i5-6400T is built on the Skylake (2015−2016) architecture. In PassMark, the Core i5-6400T scores 4,243 against the Core i3-8140U's 4,227 — a 0.4% lead for the Core i5-6400T. Geekbench 6 single-core — the metric most relevant to gaming — records 950 vs 1,225, a 25.3% lead for the Core i3-8140U that directly translates to higher frame rates. L3 cache: 6 MB on the Core i5-6400T vs 4 MB Intel® Smart Cache on the Core i3-8140U.
| Feature | Core i5-6400T | Core i3-8140U |
|---|---|---|
| Cores / Threads | 4 / 4+100% | 2 / 4 |
| Boost Clock | 2.8 GHz | 3.9 GHz+39% |
| Base Clock | 2.2 GHz+5% | 2.1 GHz |
| L3 Cache | 6 MB+50% | 4 MB Intel® Smart Cache |
| L2 Cache | 1 MB | — |
| Process | 14 nm | 14 nm |
| Architecture | Skylake (2015−2016) | — |
| PassMark | 4,243 | 4,227 |
| Cinebench R23 Multi | 2,200 | — |
| Geekbench 6 Single | 950 | 1,225+29% |
| Geekbench 6 Multi | 2,600 | — |
Memory & Platform
The Core i5-6400T uses the LGA1151 socket (PCIe 3.0), while the Core i3-8140U uses FCBGA1528 (PCIe 3.0) — making them incompatible on the same motherboard. Both support up to DDR4-2133 memory speed. Both support up to 64 GB of RAM. Both feature 2-channel memory with ECC support. Both provide 16 PCIe lanes.
| Feature | Core i5-6400T | Core i3-8140U |
|---|---|---|
| Socket | LGA1151 | FCBGA1528 |
| PCIe Generation | PCIe 3.0 | PCIe 3.0 |
| Max RAM Speed | DDR4-2133 | DDR4-2400 |
| Max RAM Capacity | 64 GB | 64 GB |
| RAM Channels | 2 | 2 |
| ECC Support | ❌ | ❌ |
| PCIe Lanes | 16 | 16 |
Advanced Features
Neither processor supports overclocking. Virtualization support: VT-x, VT-d (Core i5-6400T) vs VT-x, VT-d, EPT (Core i3-8140U). Both include integrated graphics — HD 530 (Core i5-6400T) and UHD Graphics 620 (Core i3-8140U) — useful as a fallback for troubleshooting or display output without a dedicated GPU. Primary use case: Core i5-6400T targets Budget, Core i3-8140U targets Mainstream Laptop. Direct competitor: Core i5-6400T rivals Core i3-7100; Core i3-8140U rivals Ryzen 3 3300U.
| Feature | Core i5-6400T | Core i3-8140U |
|---|---|---|
| Integrated GPU | Yes | Yes |
| IGPU Model | HD 530 | UHD Graphics 620 |
| Unlocked | No | No |
| AVX-512 | No | No |
| Virtualization | VT-x, VT-d | VT-x, VT-d, EPT |
| Target Use | Budget | Mainstream Laptop |
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