CPU Comparison
Intel Core i7-5820K vs Intel Core i7-6800K
A side-by-side comparison of specs, performance and value. The Intel Core i7-5820K is a high-end desktop (HEDT) processor built on the Haswell-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 3.3 GHz and boosting up to 3.6 GHz, 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 5820K 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.
Six cores and 12 threads provide solid throughput in multi-threaded creator applications.
Gaming
Good for gaming, but single-core speed lags behind modern CPUs.
Plays modern games well when paired with a strong GPU, though frame rates lag behind newer high-frequency CPUs.
Virtualization
Quad-channel memory and 12 threads make it great for VMs.
Quad-channel memory and PCIe lanes suit lab environments with multiple VMs and storage.
Efficiency
140W TDP on 22nm is power-hungry by modern standards.
140 W TDP and 14 nm place it behind newer platforms in performance per watt.
Specialized Performance
AI / ML
- No AI hardware
- CPU inference is moderate due to core count
- No dedicated NPUs or matrix accelerators
- Suitable for CPU-bound inference workloads only
- AVX2 support helps in some compute-heavy tasks
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
- Handles high-refresh gaming with a capable GPU
- Turbo Boost Max 3.0 can aid lightly threaded titles
- Modern CPUs typically deliver higher gaming efficiency
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- 6 cores / 12 threads
- 28 PCIe lanes
- Quad-channel DDR4 memory
- Unlocked for overclocking
Cons
- High 140W TDP
- Older 22nm process
- Only 28 PCIe lanes
- Lacks integrated graphics
Pros
- Six cores and 12 threads remain viable for productivity
- Quad-channel DDR4 provides strong memory bandwidth
- 28 PCIe 3.0 lanes enable multi-GPU and NVMe flexibility
- Unlocked multiplier for overclocking enthusiasts
- Turbo Boost Max 3.0 improves lightly threaded performance
Cons
- 140 W TDP is high by modern standards
- No integrated graphics requires a discrete GPU
- X99 platform is legacy with limited future CPU options
- PCIe lane count lower than 40-lane Broadwell-E SKUs
- Launch price higher than newer, more efficient options
Competitors & Alternatives
Intel Core i7-5820K
- AMD Ryzen 7 1700XRival
High-End Desktop
- Intel Core i7-4930KRival
High-End Desktop
- AMD FX-8350Rival
Desktop
- Compare head-to-headIntel Core i7-6800KRival
High-End Desktop
- Compare head-to-headIntel Core i7-5930KRival
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 i7-6800K
- AMD Ryzen 5 1600XRival
Mainstream Desktop
- AMD Ryzen 7 1700Rival
Creator
- AMD Ryzen 7 1800XRival
Enthusiast
- Compare head-to-headIntel Core i7-6700KRival
Mainstream Gaming
- Compare head-to-headIntel Core i7-5820KRival
Previous-Gen HEDT
More cores and higher PCIe lane count on the newer X299 platform.
Compare head-to-head- AMD Ryzen 7 5800XAlt
Much higher single-thread performance and efficiency on AM4.
- AMD Ryzen 9 5900XAlt
12 cores and 24 threads with strong performance per watt.
Modern DDR5 platform with more cores and features for new builds.
Compare head-to-head- AMD Ryzen 9 7950XAlt
Cutting-edge multi-threaded performance and PCIe 5.0 support.
Our Verdict on Each
A solid entry point into the HEDT market, offering 6 cores and DDR4 support, though aging rapidly compared to modern alternatives.
Best for: Upgrading an existing X99 system for more cores.
Read the full reviewA capable entry point into X99 HEDT with solid multi-threading and PCIe headroom, now best suited to budget used builds or specialized workloads rather than new gaming rigs.
Best for: Budget-conscious used HEDT build for multi-threaded workloads
Read the full reviewFrequently Asked Questions
Which is faster for gaming, Intel Core i7-5820K or Intel Core i7-6800K?
For gaming, the Intel Core i7-6800K leads with a gaming performance score of 78/100 among Intel Core i7-5820K and Intel Core i7-6800K.
Do Intel Core i7-5820K and Intel Core i7-6800K use the same socket?
No. They use different sockets (Intel Core i7-5820K: Intel Socket 2011-3, Intel Core i7-6800K: LGA2011-v3), so each needs a compatible motherboard.
Which is faster in multi-core benchmarks?
The Intel Core i7-5820K posts the highest multi-core benchmark score. Multi-core results: Intel Core i7-5820K (11,000). Benchmark figures are approximate and workload-dependent.