CPU Comparison
Intel Core i5-8400T vs Intel Core i7-6700
A side-by-side comparison of specs, performance and value. The Intel Core i5-8400T is a low-power desktop processor belonging to the 8th generation Coffee Lake family. Released in April 2018, it is built on the 14nm process and features 6 cores and 6 threads. Unlike the standard i5-8400, the 'T' suffix denotes a reduced 35W TDP, making it ideal for small form factor (SFF) PCs and home theater setups. The base clock is set at 1.7 GHz, with a maximum turbo boost of 3.3 GHz. 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 basic display tasks. With 16 PCIe 3.0 lanes, it provides adequate expansion options. The i5-8400T is compatible with LGA 1151 sockets, though it requires 300-series chipsets for official support, offering a balance of efficiency and multi-core capability.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
6 cores handle office tasks easily, though single-core is slower.
Handles office workloads and multitasking without issues.
Gaming
Can handle light gaming, but low clocks limit high-refresh gaming.
Good for 60fps gaming with a discrete GPU, but struggles with modern high-refresh titles.
Virtualization
Good for 1-2 VMs, but lacks hyper-threading.
Capable of running 1-2 light VMs.
Efficiency
Outstanding efficiency with a 35W TDP.
Highly efficient 65W design.
Specialized Performance
AI / ML
- No dedicated AI hardware.
- Low clocks make inference slow.
- No AI hardware
- CPU inference is slow
Content Creation
Gaming
- Low base clock can cause stuttering in CPU-bound games.
- UHD 630 is only good for very light titles.
- Best paired with a low-end discrete GPU if gaming.
- Needs a discrete GPU for modern gaming
- Quad-core design is aging for new AAA games
- Great for older or esports titles
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- Extremely low 35W TDP
- 6 cores for parallel tasks
- Runs very cool
- Good for small form factor builds
Cons
- Low base and boost clocks
- Locked multiplier
- No Hyper-Threading
- End-of-life platform
Pros
- Excellent power efficiency (65W)
- Solid single-core performance
- Supports DDR4 memory
- Good integrated graphics
Cons
- Only 4 cores
- Locked multiplier
- No PCIe 4.0
- Outdated platform
Competitors & Alternatives
Intel Core i5-8400T
- AMD Ryzen 5 2400GERival
Low Power Desktop
- Compare head-to-headIntel Core i5-8400Rival
Mainstream Desktop
- AMD Ryzen 5 2600ERival
Low Power Desktop
- Compare head-to-headIntel Core i5-7400TRival
Previous Gen Low Power
- AMD Ryzen 3 2200GERival
Budget Low Power
Slightly faster clocks, same TDP.
Compare head-to-head- AMD Ryzen 5 3400GEAlt
Better integrated graphics.
Much faster modern architecture.
Compare head-to-head- AMD Ryzen 5 5600GEAlt
Better efficiency and performance.
Slightly higher clocks if buying used.
Compare head-to-head
Intel Core i7-6700
- AMD FX-8350Rival
Desktop
- AMD FX-8370Rival
Desktop
- Compare head-to-headIntel Core i5-6600Rival
Desktop
- Compare head-to-headIntel Core i7-4790Rival
Desktop
- AMD A10-7890KRival
Desktop
- Intel Core i7-7700Alt
Slightly faster with better clock speeds.
- Intel Core i5-12400FAlt
Vastly superior modern alternative for budget builds.
- AMD Ryzen 5 5500Alt
More cores, better modern value.
Cheaper, 6 cores, better performance.
Compare head-to-head- AMD Ryzen 5 3600Alt
Legacy alternative with much better multi-threading.
Our Verdict on Each
A highly efficient 6-core processor perfect for compact builds, though its low clock speeds limit performance compared to the standard 8400.
Best for: Building a quiet home server or retro gaming rig on a budget.
Read the full reviewA reliable and efficient quad-core CPU that was the gold standard for mainstream desktop computing in 2015, still capable of basic tasks today.
Best for: Upgrading an older LGA 1151 system for budget 1080p gaming.
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i5-8400T or Intel Core i7-6700?
Based on our editorial ratings, the Intel Core i7-6700 comes out ahead with a score of 8/10. 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 i5-8400T or Intel Core i7-6700?
For gaming, the Intel Core i7-6700 leads with a gaming performance score of 65/100 among Intel Core i5-8400T and Intel Core i7-6700.
Which uses less power?
The Intel Core i5-8400T has the lowest rated TDP. Power draw across these chips: Intel Core i5-8400T (35 W), Intel Core i7-6700 (65 W).
Do Intel Core i5-8400T and Intel Core i7-6700 use the same socket?
No. They use different sockets (Intel Core i5-8400T: LGA 1151, Intel Core i7-6700: Intel Socket 1151), so each needs a compatible motherboard.
Which has more cores?
The Intel Core i5-8400T has the most cores. Core counts: Intel Core i5-8400T (6 cores), Intel Core i7-6700 (4 cores).
Which is faster in multi-core benchmarks?
The Intel Core i5-8400T posts the highest multi-core benchmark score. Multi-core results: Intel Core i5-8400T (8,500), Intel Core i7-6700 (7,500). Benchmark figures are approximate and workload-dependent.