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
Gaming
Virtualization
Efficiency
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.