CPU Comparison

Intel Core i9-7920X X-series vs Intel Core i9-7940X

A side-by-side comparison of specs, performance and value. The Intel Core i9-7920X is a 12-core, 24-thread high-end desktop processor built on Skylake-X with quad-channel DDR4-2666 memory, up to 44 PCIe 3.0 lanes, and no integrated graphics. Designed for X299 platforms, it targets enthusiasts, creators, and workstation users who need multi-core throughput and I/O expansion in a desktop form factor.

Top pick
Intel · Core X-Series
Intel Core i9-7920X X-series
12C / 24T4.3 GHz140 W
7.9
Full review
Intel · Core X-Series
Intel Core i9-7940X
14C / 28T4.4 GHz165 W
7.5
Full review

The Bottom Line

Overview & Launch

Brand
Intel
Intel
Market
High-End Desktop
High-End Desktop
Generation
7th Gen X-Series (Skylake-X)
7th Gen X-Series
Launched
2017
2017
Status
Discontinued
Discontinued
Codename
Skylake-X
Skylake-X
Series
Core X-Series
Core X-Series
Family
Intel Core X-series Processors
Skylake-X
Predecessor
Intel Core i7-7820X (10-core)
Intel Core i7-6950X
Successor
Intel Core i9-9920X (Cascade Lake-X refresh)
Intel Core i9-9940X

Specifications Compared

Cores & Clocks
Cores
12
14
Threads
24
28
Base Clock
2.9 GHz
3.1 GHz
Boost Clock
4.3 GHz
4.4 GHz
Cache & Power
L3 Cache
16.5 MB
19.25 MB
TDP
140 W
165 W
Architecture
Architecture
Skylake-X
Skylake-X
Process Node
14 nm
14nm
Memory
Memory Type
DDR4
DDR4
Memory Speed
DDR4-2666
DDR4-2666
Memory Channels
Quad (4)
Quad (4)
Max Memory
128 GB
128 GB
Platform & I/O
Socket
LGA2066
LGA 2066
PCIe Version
PCIe 3.0
PCIe 3.0
PCIe Lanes
44
44
Integrated GPU
None
None
Unlocked
Yes
Yes

Performance Compared

Productivity

Intel Core i9-7920X X-seriesBest86
Intel Core i9-7940X80

Gaming

Intel Core i9-7920X X-seriesBest78
Intel Core i9-7940X75

Virtualization

Intel Core i9-7920X X-seriesBest88
Intel Core i9-7940X85

Efficiency

Intel Core i9-7920X X-seriesBest58
Intel Core i9-7940X40

Specialized Performance

AI / ML

Intel Core i9-7920X X-seriesLimited
  • No dedicated AI acceleration hardware.
  • Suitable for CPU-based inference or traditional machine learning preprocessing.
  • Workloads heavily dependent on modern AI accelerators will run much slower.
Intel Core i9-7940XLimited
  • AVX-512 helps with some vector calculations
  • No dedicated AI acceleration hardware
  • CPU-based inference is significantly slower than modern NPUs or GPUs

Content Creation

Intel Core i9-7920X X-seriesVery Good
Adobe Premiere ProDaVinci ResolveBlenderCinema 4DAfter EffectsCode Compilation
Intel Core i9-7940XVery Good
Adobe Premiere ProBlenderAutodesk MayaHandbrakeDaVinci Resolve

Gaming

Intel Core i9-7920X X-seriesGood
  • Sufficient for high-refresh gaming when paired with a strong GPU.
  • Turbo Boost Max 3.0 can elevate single-core performance for less threaded titles.
  • Modern gaming CPUs tend to offer better efficiency and higher sustained clocks.
Intel Core i9-7940XGood
  • High clock speeds help push frames in CPU-bound scenarios
  • Mesh architecture adds slight latency compared to ring bus designs
  • Lacks the cache size and IPC of modern gaming CPUs

Industry Impact

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

Best CPU by Use Case

4K Video Editing
Very Good
Very Good
3D Rendering
Very Good
Very Good
Software Compilation
Very Good
Game Streaming
Good
Gaming
Good
Multi-GPU Compute
Excellent
Virtual Machines
Good
Modern Gaming
Fair

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 i9-7920X X-series

Pros

  • 12 cores and 24 threads
  • Quad-channel DDR4-2666 memory support
  • Up to 44 PCIe 3.0 lanes for expansion
  • Unlocked multiplier for overclocking
  • Turbo Boost Max 3.0 for lightly threaded tasks
  • AVX-512 instruction support
  • Strong multi-threaded performance for its time

Cons

  • High power consumption under load
  • No integrated graphics
  • Platform (X299/LGA2066) is discontinued
  • Newer platforms offer better efficiency and value
  • PCIe 3.0 instead of newer generations
Intel Core i9-7940X

Pros

  • 14 cores and 28 threads
  • 44 PCIe 3.0 lanes for expansive I/O
  • Quad-channel DDR4 memory support
  • AVX-512 instruction support
  • Unlocked multiplier for overclocking

Cons

  • Runs extremely hot under heavy loads
  • High power consumption for the performance delivered
  • Lacks integrated graphics
  • Discontinued and outdated platform
  • Outpaced by modern mainstream CPUs in efficiency and IPC

Competitors & Alternatives

Intel Core i9-7920X X-series

  • AMD Ryzen Threadripper 1920X

    Workstation

    Rival
  • AMD Ryzen Threadripper 1950X

    Workstation

    Rival
  • AMD Ryzen 9 3900X

    Creator

    Rival
  • AMD Ryzen 9 3950X

    Creator

    Rival
  • Rival
    Compare head-to-head
  • Cascade Lake-X refresh with improved features and clocks on X299.

    Compare head-to-head
  • AMD Ryzen 9 5900X
    Alt

    Stronger efficiency and gaming performance on AM4 platform.

  • AMD Ryzen 9 7900
    Alt

    Modern AM5 platform with DDR5 and PCIe 5.0 for new builds.

  • AMD Threadripper 3000/4000 series
    Alt

    Higher core counts and more I/O for professional workstations.

  • Intel Core i7-14700K
    Alt

    Good mainstream alternative for gaming and content creation with lower power.

Intel Core i9-7940X

  • AMD Ryzen Threadripper 1950X

    Workstation

    Rival
  • AMD Ryzen Threadripper 1920X

    Workstation

    Rival
  • Intel Core i9-7960X

    High-End Desktop

    Rival
    Compare head-to-head
  • Intel Core i9-7900X

    High-End Desktop

    Rival
  • Intel Core i7-7820X

    High-End Desktop

    Rival
  • Newer Cascade Lake-X alternative on the same platform with better value and refined behavior.

    Compare head-to-head
  • AMD Ryzen 9 5900X
    Alt

    Much more efficient, faster single-core, and relies on a modern AM4 platform.

  • Intel Core i7-13700K
    Alt

    Massively faster single-core and multi-core performance with modern features at a lower power draw.

  • Modern platform with DDR5 and PCIe 5.0, offering vastly superior efficiency.

    Compare head-to-head
  • Top-tier modern performance for any workload, leaving the 7940X far behind.

    Compare head-to-head

Our Verdict on Each

A capable HEDT chip with strong multi-threaded performance and ample I/O, but power-hungry by modern standards and best pursued used or for legacy X299 builds.

Best for: Upgrading or completing an existing LGA2066/X299 build at a low used price

Read the full review

A potent HEDT processor for its time, the i9-7940X offers strong multi-core capabilities but suffers from high heat output and is outpaced by modern mainstream chips.

Best for: Upgrading an existing LGA 2066 workstation on a tight budget.

Read the full review

Frequently Asked Questions

Which is better, Intel Core i9-7920X X-series or Intel Core i9-7940X?

Based on our editorial ratings, the Intel Core i9-7920X X-series comes out ahead with a score of 7.9/10. 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 i9-7920X X-series or Intel Core i9-7940X?

For gaming, the Intel Core i9-7920X X-series leads with a gaming performance score of 78/100 among Intel Core i9-7920X X-series and Intel Core i9-7940X.

Which uses less power?

The Intel Core i9-7920X X-series has the lowest rated TDP. Power draw across these chips: Intel Core i9-7920X X-series (140 W), Intel Core i9-7940X (165 W).

Do Intel Core i9-7920X X-series and Intel Core i9-7940X use the same socket?

No. They use different sockets (Intel Core i9-7920X X-series: LGA2066, Intel Core i9-7940X: LGA 2066), so each needs a compatible motherboard.

Which has more cores?

The Intel Core i9-7940X has the most cores. Core counts: Intel Core i9-7920X X-series (12 cores), Intel Core i9-7940X (14 cores).