CPU Comparison
Intel Core i7-6800K vs Intel Core i7-5820K
A side-by-side comparison of specs, performance and value. The Intel Core i7-6800K is a high-end desktop (HEDT) processor built on the Broadwell-E architecture. Designed for enthusiasts and professionals, it features six cores and twelve threads, offering a significant multi-threaded performance leap over mainstream quad-core CPUs of its era. Operating at a base frequency of 3.4 GHz and boosting up to 3.8 GHz with Intel Turbo Boost Max 3.0, it delivers robust computing power for demanding applications. Unlike mainstream chips, it utilizes the LGA 2011-v3 socket and the X99 chipset, supporting quad-channel DDR4 memory for massive memory bandwidth. With 28 PCIe 3.0 lanes, it provides extensive expansion capabilities for multi-GPU setups and high-speed storage arrays. The 140-watt TDP reflects its workstation-class design. While it lacks integrated graphics, requiring a discrete GPU, the 6800K excels in parallel processing tasks like video editing, 3D rendering, and virtualization, making it a powerhouse for creators who need more than standard desktop platforms offer.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
6 cores handle rendering well, but lack the speed of modern architectures.
Solid performance for older software and moderate rendering tasks, but falls behind modern 6-core CPUs in IPC and clock speed.
Gaming
Good for gaming, but single-core speed lags behind modern CPUs.
Playable in modern esports and AAA titles when paired with a strong GPU, but likely to bottleneck top-tier cards in CPU-intensive scenarios.
Virtualization
Quad-channel memory and 12 threads make it great for VMs.
Excellent value for home labs due to high core count, VT-d support, and PCIe lane availability for multiple NICs or storage controllers.
Efficiency
140W TDP is power-hungry by modern standards.
High power consumption (140W TDP) and heat output compared to 14nm, 10nm, or 7nm counterparts.
Specialized Performance
AI / ML
- No AI hardware
- CPU inference is moderate due to core count
- No dedicated AI or matrix acceleration hardware.
- AVX2 support offers some vector compute capability.
Content Creation
Gaming
- Can handle modern games with a discrete GPU
- Lower single-core speed limits high-refresh gaming
- Great for multi-tasking while gaming
- Requires discrete graphics; no integrated GPU.
- PCIe 3.0 lanes limit full potential of modern RTX 40-series GPUs.
- Boost clocks are modest by modern standards.
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- 6 cores / 12 threads
- 28 PCIe lanes
- Quad-channel memory
- Unlocked for overclocking
Cons
- High 140W TDP
- Older 14nm process
- Only 28 PCIe lanes
- Lacks integrated graphics
Pros
- Relatively low entry cost for a used HEDT platform
- Quad-channel DDR4 memory support
- 28 PCIe lanes allow for multiple expansion cards
- Unlocked for overclocking
- Strong multi-core performance for its era
Cons
- High power draw and heat output
- No integrated graphics
- Limited to 28 PCIe lanes (fewer than 5930K/5960X)
- Requires expensive X99 motherboards and DDR4 RAM
- Older architecture lacks modern instruction sets like AVX-512
Competitors & Alternatives
Intel Core i7-6800K
- AMD Ryzen 7 1700XRival
High-End Desktop
- Compare head-to-headIntel Core i7-5820KRival
High-End Desktop
- AMD Ryzen 7 1700Rival
High-End Desktop
- Compare head-to-headIntel Core i7-7800XRival
High-End Desktop
- Compare head-to-headIntel Core i7-6850KRival
High-End Desktop
- AMD Ryzen 5 5600XAlt
Vastly superior single-core speed and efficiency.
- Intel Core i5-12400FAlt
Modern alternative that beats it in almost everything.
- AMD Ryzen 7 5700XAlt
8 cores, better IPC, lower power.
Intel Core i7-5820K
- AMD Ryzen 5 1600Rival
Mainstream
- AMD Ryzen 7 1700Rival
Creator
- Compare head-to-headIntel Core i7-4790KRival
Gaming
- AMD FX-9590Rival
Enthusiast
- Compare head-to-headIntel Core i7-6800KRival
Workstation
If you need the full 40 PCIe lanes for tri-SI or heavy storage arrays.
Compare head-to-head- AMD Ryzen 5 5600Alt
A modern, significantly faster and more efficient gaming CPU.
Modern platform with PCIe 5.0 and DDR5 support.
Compare head-to-head- AMD Ryzen 9 5900XAlt
Massive multi-core performance jump for content creation.
More cores and higher frequency on a still-recent mainstream platform.
Compare head-to-head
Our Verdict on Each
A solid entry point into the HEDT market, offering 6 cores and 28 PCIe lanes, though aging rapidly compared to modern alternatives.
Best for: Upgrading an existing X99 system for more cores.
Read the full reviewThe i7-5820K was a groundbreaking value proposition in 2014, bringing DDR4 and quad-channel memory to a lower price point. Today, it remains viable only for budget builds, handicapped by high power consumption and limited PCIe lanes compared to modern standards.
Best for: Building a budget-friendly used workstation for virtualization or light content creation.
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i7-6800K or Intel Core i7-5820K?
Based on our editorial ratings, the Intel Core i7-6800K 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.
Do Intel Core i7-6800K and Intel Core i7-5820K use the same socket?
No. They use different sockets (Intel Core i7-6800K: Intel Socket 2011-3, Intel Core i7-5820K: FCLGA2011-3 (LGA2011-v3)), so each needs a compatible motherboard.
Which is faster in multi-core benchmarks?
The Intel Core i7-6800K posts the highest multi-core benchmark score. Multi-core results: Intel Core i7-6800K (13,000). Benchmark figures are approximate and workload-dependent.