CPU Comparison

Core i5-7640X vs Core i7-7740X

A side-by-side comparison of specs, performance and value. The Intel Core i5-7640X is a unique entry in Intel's 7th generation lineup, blurring the lines between mainstream and high-end desktop (HEDT) platforms. Released on June 26, 2017, it was part of the Kaby Lake-X family, designed for the LGA 2066 socket. Unlike traditional Core i5 processors of its era, the 7640X featured an unlocked multiplier, allowing enthusiasts to push the 3.9 GHz base clock well beyond its 4.3 GHz turbo limit. However, it also carried quirks: it only supported dual-channel memory despite being on a quad-channel platform, and lacked integrated graphics. Aimed at gamers and budget-conscious overclockers wanting access to the X299 chipset, its position in the market was somewhat controversial, as it offered fewer PCIe lanes than its larger siblings. Despite this, it provided excellent single-threaded performance for its time and remains an interesting footnote in Intel's HEDT strategy.

Top pick
Intel · Core i5
Core i5-7640X
4C / 4T4.3 GHz112 W
6.5
Full review
Intel · X-Series 7th Gen
Core i7-7740X
4C / 8T4.6 GHz112 W
6
Full review

The Bottom Line

Overview & Launch

Brand
Intel
Intel
Market
Desktop
Desktop
Segment
High-End Desktop
High-End Desktop
Generation
7th Gen (Kaby Lake-X)
7th Gen X-Series
Launched
2017
2017
Status
End-of-life
Active
Codename
Kaby Lake-X
Kaby Lake-X
Series
Core i5
X-Series 7th Gen
Family
X-Series
Kaby Lake-X
Predecessor
Intel Core i5-6600K
Core i7-6700K
Successor
Intel Core i5-9600K
N/A

Specifications Compared

Cores & Clocks
Cores
4
4
Threads
4
8
Base Clock
3.9 GHz
4.3 GHz
Boost Clock
4.3 GHz
4.6 GHz
Cache & Power
L3 Cache
6 MB
8 MB
TDP
112 W
112 W
Architecture
Architecture
Kaby Lake-X
Kaby Lake-X
Process Node
14nm
14nm
Memory
Memory Type
DDR4
DDR4
Memory Speed
DDR4-2666
2666 MT/s
Memory Channels
Dual (2)
Dual (2)
Max Memory
64 GB
128 GB
Platform & I/O
Socket
LGA 2066
LGA 2066
PCIe Version
PCIe 3.0
PCIe 3.0
PCIe Lanes
16
16
Integrated GPU
None
None
Unlocked
Yes
Yes

Specialized Performance

AI / ML

Core i5-7640XPoor
  • No dedicated AI hardware
  • Low core count limits CPU-based inference
Core i7-7740X

No data

Content Creation

Core i5-7640XFair
Basic Photo EditingAudio Production
Core i7-7740X

No data

Gaming

Core i5-7640XGood
  • High clock speeds benefit high-refresh-rate gaming
  • 4 cores struggle with modern CPU-intensive titles
  • Requires a dedicated GPU
Core i7-7740X

No data

Industry Impact

Gaming
Low
Low
Workstations
Low
Low
Content Creation
Low
Low
Virtualization
Low
Low

Best CPU by Use Case

1080p Gaming
Very Good
Competitive eSports
Excellent
Heavy Multitasking
Poor
Video Editing
Fair
Extreme Overclocking
Very Good
General Workstation
Poor

Target Audience

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

Strengths & Weaknesses

Core i5-7640X

Pros

  • Unlocked multiplier for overclocking
  • High 4.3 GHz turbo frequency
  • Access to X299 chipset features
  • Strong single-core performance for its era

Cons

  • Only 4 cores and 4 threads
  • Limited to dual-channel memory
  • Only 16 PCIe lanes
  • Lacks integrated graphics
  • Poor price-to-performance ratio at launch
Core i7-7740X

Pros

  • High single-core frequencies
  • Unlocked for overclocking
  • Access to X299 chipset features

Cons

  • Only 4 cores on an HEDT platform
  • Limited to dual-channel memory
  • No integrated graphics
  • Poor value compared to true HEDT or mainstream parts

Competitors & Alternatives

Core i5-7640X

Core i7-7740X

  • Intel Core i7-7700K

    Performance Desktop

    Rival
  • Intel Core i7-7800X

    High-End Desktop

    Rival
    Compare head-to-head
  • AMD Ryzen 7 1800X

    High-End Desktop

    Rival
  • Intel Core i5-7640X

    High-End Desktop

    Rival
  • AMD Ryzen 5 1600X

    Performance Desktop

    Rival
  • AMD Ryzen 7 1700
    Alt

    More cores and better multi-threading for less money.

  • Actual high-end HEDT performance.

    Compare head-to-head
  • AMD Threadripper 1900X
    Alt

    Better HEDT platform features and core count.

Our Verdict on Each

Core i5-7640XSituational

A peculiar HEDT chip with high clock speeds but limited PCIe lanes and no Hyper-Threading, making it a niche product for overclockers rather than a true workstation CPU.

Best for: Hobbyist overclocking on a used X299 motherboard

Read the full review
Core i7-7740XSituational

An oddity in Intel's lineup, offering high clocks but limited core count and features for the HEDT platform. Hard to recommend over mainstream alternatives.

Best for: Niche collection or specific legacy X299 troubleshooting

Read the full review

Frequently Asked Questions

Which is better, Core i5-7640X or Core i7-7740X?

Based on our editorial ratings, the Core i5-7640X comes out ahead with a score of 6.5/10. That said, the best choice depends on your workload — check the spec and performance breakdown above for gaming, productivity and efficiency differences.

Do Core i5-7640X and Core i7-7740X use the same socket?

Yes — all of these CPUs use the LGA 2066 socket, so they share compatible motherboards.

Which is faster in multi-core benchmarks?

The Core i7-7740X posts the highest multi-core benchmark score. Multi-core results: Core i7-7740X (0). Benchmark figures are approximate and workload-dependent.