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.

Intel · Core i7
Intel Core i7-5820K
6C / 12T3.6 GHz140 W
8
Full review
Intel · Core i7
Intel Core i7-6800K
6C / 12T3.6 GHz140 W
8
Full review

The Bottom Line

Overview & Launch

Brand
Intel
Intel
Market
Desktop
High-End Desktop
Segment
High-End Desktop
Generation
Core i7 (Haswell-E)
6th Gen HEDT (Broadwell-E)
Launched
2014
2016
Status
End-of-life
Discontinued
Codename
Haswell-E
Broadwell-E
Series
Core i7
Core i7
Family
5th Generation
Broadwell-E (Core i7)
Predecessor
Intel Core i7-4930K
Intel Core i7-5820K
Successor
Intel Core i7-6800K
Intel Core i7-7820X

Specifications Compared

Cores & Clocks
Cores
6
6
Threads
12
12
Base Clock
3.3 GHz
3.4 GHz
Boost Clock
3.6 GHz
3.6 GHz
Cache & Power
L3 Cache
15 MB
15 MB
TDP
140 W
140 W
Architecture
Architecture
Haswell-E
Broadwell-E
Process Node
22nm
14 nm
Memory
Memory Type
DDR4
DDR4
Memory Speed
2133 MT/s
DDR4-2400/2133
Memory Channels
Quad (4)
Quad (4)
Max Memory
128 GB
128 GB
Platform & I/O
Socket
Intel Socket 2011-3
LGA2011-v3
PCIe Version
Gen 3
3.0
PCIe Lanes
28
28
Integrated GPU
None
None
Unlocked
Yes
Yes

Performance Compared

Productivity

Intel Core i7-5820K72

6 cores handle rendering well, but lack the speed of modern architectures.

Intel Core i7-6800KBest85

Six cores and 12 threads provide solid throughput in multi-threaded creator applications.

Gaming

Intel Core i7-5820K60

Good for gaming, but single-core speed lags behind modern CPUs.

Intel Core i7-6800KBest78

Plays modern games well when paired with a strong GPU, though frame rates lag behind newer high-frequency CPUs.

Virtualization

Intel Core i7-5820K78

Quad-channel memory and 12 threads make it great for VMs.

Intel Core i7-6800KBest86

Quad-channel memory and PCIe lanes suit lab environments with multiple VMs and storage.

Efficiency

Intel Core i7-5820K35

140W TDP on 22nm is power-hungry by modern standards.

Intel Core i7-6800KBest60

140 W TDP and 14 nm place it behind newer platforms in performance per watt.

Specialized Performance

AI / ML

Intel Core i7-5820KLimited
  • No AI hardware
  • CPU inference is moderate due to core count
Intel Core i7-6800KBasic
  • No dedicated NPUs or matrix accelerators
  • Suitable for CPU-bound inference workloads only
  • AVX2 support helps in some compute-heavy tasks

Content Creation

Intel Core i7-5820KVery Good
Premiere ProBlenderAutoCADDaVinci Resolve
Intel Core i7-6800KVery Good
Adobe Premiere ProDaVinci ResolveBlenderCinema 4DAfter Effects7-Zip / HandBrake

Gaming

Intel Core i7-5820KGood
  • Can handle modern games with a discrete GPU
  • Lower single-core speed limits high-refresh gaming
  • Great for multi-tasking while gaming
Intel Core i7-6800KGood
  • 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

Gaming
Moderate
Moderate
Workstations
High
High
Content Creation
High
High
Virtualization
High
High

Best CPU by Use Case

4K Video Editing
Very Good
Very Good
3D Rendering
Very Good
Very Good
Virtual Machines
Excellent
Very Good
1440p Gaming
Good
Compilation
Excellent
Software Development
Good
Gaming
Good

Target Audience

Gamers
Targeted
Targeted
Content Creators
Targeted
Targeted
Developers
Targeted
Targeted
Workstation Users
Targeted
Targeted
Streamers
Targeted
Targeted
Office / Productivity
Students

Strengths & Weaknesses

Intel Core i7-5820K

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
Intel Core i7-6800K

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 1700X

    High-End Desktop

    Rival
  • Intel Core i7-4930K

    High-End Desktop

    Rival
  • AMD FX-8350

    Desktop

    Rival
  • Intel Core i7-6800K

    High-End Desktop

    Rival
    Compare head-to-head
  • Intel Core i7-5930K

    High-End Desktop

    Rival
    Compare head-to-head
  • AMD Ryzen 5 5600X
    Alt

    Vastly superior single-core speed and efficiency.

  • Intel Core i5-12400F
    Alt

    Modern alternative that beats it in almost everything.

  • AMD Ryzen 7 5700X
    Alt

    8 cores, better IPC, lower power.

Intel Core i7-6800K

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 review

A 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 review

Frequently 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.