CPU Comparison
Core i5-6400 vs Intel Core i7-6700
A side-by-side comparison of specs, performance and value. The Intel Core i5-6400 is a 6th generation desktop processor launched in July 2015 as part of the Skylake architecture. Designed for the LGA 1151 socket, it brought the 14nm manufacturing process to the mainstream market. This quad-core processor operates at a base frequency of 2.7 GHz and boosts up to 3.3 GHz. Unlike its predecessor, the 6400 natively supports DDR4 memory alongside DDR3L, offering a transitional platform for motherboard manufacturers. It features 6MB of L3 cache and a modest 65W TDP, making it highly energy efficient for its time. The inclusion of Intel HD Graphics 530 provided competent integrated graphics for non-gaming workloads. While it lacked an unlocked multiplier, it became a favorite for budget builders and system integrators. Its reliable quad-core performance made it a staple in office PCs and budget gaming rigs when paired with a dedicated GPU, serving as a workhorse for years before multi-threading demands outpaced its capabilities.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Sufficient for basic office applications and web browsing, but struggles with heavy multitasking.
Handles office workloads and multitasking without issues.
Gaming
Severely bottlenecks modern GPUs. Only playable in older or very light eSports titles.
Good for 60fps gaming with a discrete GPU, but struggles with modern high-refresh titles.
Virtualization
Limited to very light virtualization due to 4 threads.
Capable of running 1-2 light VMs.
Efficiency
Efficient for its time, but superseded by modern 10nm/Intel 7 processes.
Highly efficient 65W design.
Specialized Performance
AI / ML
- No AI acceleration
- Insufficient threads for modern AI workloads
- No AI hardware
- CPU inference is slow
Content Creation
Gaming
- Low base clock limits frame rates
- 4 cores cause stuttering in modern games
- Acceptable only for retro 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
- Low 65W TDP for easy cooling
- Supports both DDR4 and DDR3L memory
- Solid single-core performance for its generation
- Includes HD Graphics 530 for display tasks
Cons
- Only 4 cores and 4 threads
- Low base clock of 2.7 GHz
- Locked multiplier prevents overclocking
- Not supported by Windows 11
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
Core i5-6400
- AMD FX-8350Rival
Desktop
- Compare head-to-headIntel Core i5-6500Rival
Desktop
- AMD FX-6300Rival
Desktop
- Intel Core i3-6100Rival
Desktop
- AMD Ryzen 5 1400Rival
Desktop
Vastly better performance and platform for a similar budget.
Compare head-to-head- AMD Ryzen 5 3600Alt
More cores and threads for better multi-threaded workloads.
Slight performance bump on the same socket if upgrading cheaply.
Compare head-to-headHyper-threading on the same socket for better multi-core performance.
Compare head-to-head- AMD Ryzen 5 2600Alt
Modern alternative with more threads and better upgrade path.
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
The Core i5-6400 was a fantastic budget CPU in 2015, but its 4-core/4-thread design and low clock speeds make it heavily outdated for modern gaming and productivity.
Best for: Building a retro gaming PC or basic office machine from used parts
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, Core i5-6400 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, Core i5-6400 or Intel Core i7-6700?
For gaming, the Intel Core i7-6700 leads with a gaming performance score of 65/100 among Core i5-6400 and Intel Core i7-6700.
Do Core i5-6400 and Intel Core i7-6700 use the same socket?
No. They use different sockets (Core i5-6400: LGA 1151, Intel Core i7-6700: Intel Socket 1151), so each needs a compatible motherboard.
Which is faster in multi-core benchmarks?
The Intel Core i7-6700 posts the highest multi-core benchmark score. Multi-core results: Intel Core i7-6700 (7,500). Benchmark figures are approximate and workload-dependent.