CPU Comparison
Intel Core i7-5820K vs Intel Core i7-7800X
A side-by-side comparison of specs, performance and value. The Intel Core i7-5820K is a six-core enthusiast processor that introduced the X99 platform and DDR4 memory to the high-end desktop market, offering a balance of multi-threaded performance and affordability.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Solid performance for older software and moderate rendering tasks, but falls behind modern 6-core CPUs in IPC and clock speed.
Handles multi-threaded productivity tasks reasonably well, though newer platforms overtake it in performance-per-watt.
Gaming
Playable in modern esports and AAA titles when paired with a strong GPU, but likely to bottleneck top-tier cards in CPU-intensive scenarios.
Adequate for 1080p and 1440p with a strong GPU, but modern gaming CPUs deliver higher frame rates and better efficiency.
Virtualization
Excellent value for home labs due to high core count, VT-d support, and PCIe lane availability for multiple NICs or storage controllers.
Quad-channel memory and 12 threads suit multiple VMs and developer workloads.
Efficiency
High power consumption (140W TDP) and heat output compared to 14nm, 10nm, or 7nm counterparts.
High power draw relative to performance makes it less efficient than current-generation chips.
Specialized Performance
AI / ML
- No dedicated AI or matrix acceleration hardware.
- AVX2 support offers some vector compute capability.
- AVX-512 accelerates some inference workloads on CPU
- No dedicated NPU or matrix engines
- Suitable only for light or experimental AI workloads
Content Creation
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.
- Supports high-refresh gaming with capable GPUs
- Lacks the single-thread uplift of newer architectures
- Requires discrete graphics
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
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
Pros
- Quad-channel DDR4 memory
- Unlocked for overclocking
- AVX-512 support
- 12 threads for multi-threaded workloads
- 28 PCIe 3.0 lanes from CPU
Cons
- No integrated graphics
- Higher power consumption relative to modern CPUs
- Only 28 PCIe lanes vs higher-tier X-series SKUs
- Discontinued platform with limited upgrade path
- Memory officially limited to DDR4-2400
Competitors & Alternatives
Intel Core i7-5820K
- AMD Ryzen 5 1600Rival
Mainstream
- AMD Ryzen 7 1700Rival
Creator
- Intel 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.
- Intel Core i5-12600KAlt
Modern platform with PCIe 5.0 and DDR5 support.
- 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
Intel Core i7-7800X
- AMD Ryzen 7 1700Rival
Creator
- AMD Ryzen 7 1800XRival
Creator
- AMD Ryzen Threadripper 1920XRival
Workstation
- AMD Ryzen Threadripper 1950XRival
Workstation
- Intel Core i7-7820XRival
HEDT
- Intel Core i7-9700KAlt
Higher gaming performance on mainstream platform with lower power draw.
- AMD Ryzen 9 3900XAlt
More cores, higher efficiency, and newer platform with PCIe 4.0 support.
- Intel Core i9-9900KAlt
Strong single-thread performance suitable for gaming and productivity.
- AMD Ryzen 7 5800XAlt
Modern Zen 3 architecture with excellent single and multi-threaded performance.
- Intel Core i7-13700KAlt
Current-gen hybrid architecture with high core counts and PCIe 5.0.
Our Verdict on Each
The 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 reviewThe i7-7800X offers quad-channel memory and decent multi-core performance for its era, but higher power draw and limited PCIe lanes make it a niche choice today versus modern mainstream platforms.
Best for: Budget upgrade on existing X299 platform with DDR4 investment
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i7-5820K or Intel Core i7-7800X?
Based on our editorial ratings, the Intel Core i7-5820K comes out ahead with a score of 7.5/10. 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 i7-5820K or Intel Core i7-7800X?
For gaming, the Intel Core i7-7800X leads with a gaming performance score of 76/100 among Intel Core i7-5820K and Intel Core i7-7800X.
Do Intel Core i7-5820K and Intel Core i7-7800X use the same socket?
No. They use different sockets (Intel Core i7-5820K: FCLGA2011-3 (LGA2011-v3), Intel Core i7-7800X: LGA2066), so each needs a compatible motherboard.