CPU Comparison

Core i5-7640X vs Intel 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.

Intel · Core i5
Core i5-7640X
4C / 4T4.3 GHz112 W
6.5
Full review
Top pick
Intel · Core i7
Intel Core i7-7740X
4C / 8T4.5 GHz112 W
7
Full review

The Bottom Line

Overview & Launch

Brand
Intel
Intel
Market
Desktop
Desktop
Segment
High-End Desktop
Generation
7th Gen (Kaby Lake-X)
7th Gen X-Series (Kaby Lake-X)
Launched
2017
2017
Status
End-of-life
Discontinued
Codename
Kaby Lake-X
Kaby Lake-X
Series
Core i5
Core i7
Family
X-Series
X-Series 7th Gen (Core i7)
Predecessor
Intel Core i5-6600K
Intel Core i7-7700K (mainstream)
Successor
Intel Core i5-9600K
Platform superseded by Skylake-X and later HEDT/enthusiast lines

Specifications Compared

Cores & Clocks
Cores
4
4
Threads
4
8
Base Clock
3.9 GHz
4.3 GHz
Boost Clock
4.3 GHz
4.5 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
14 nm
Memory
Memory Type
DDR4
DDR4
Memory Speed
DDR4-2666
DDR4-2666
Memory Channels
Dual (2)
Dual (2)
Max Memory
64 GB
64 GB
Platform & I/O
Socket
LGA 2066
LGA2066
PCIe Version
PCIe 3.0
PCIe 3.0
PCIe Lanes
16
16
Integrated GPU
None
None
Unlocked
Yes
Yes

Performance Compared

Productivity

Core i5-7640X

Adequate for basic office tasks and light workloads, but falls behind in heavily multi-threaded applications.

Intel Core i7-7740X68

Quad-core limits performance in heavily parallelized applications compared to higher core-count alternatives.

Gaming

Core i5-7640X

Performs well in older or less demanding games due to high IPC and clock speeds, but bottlenecks modern titles due to 4-core/4-thread limitations.

Intel Core i7-7740X78

Paired with a strong discrete GPU, the high clocks enable smooth high-refresh gaming, though newer platforms offer better efficiency and future-proofing.

Virtualization

Core i5-7640X

Limited utility for virtualization due to the lack of Hyper-Threading and low core count.

Intel Core i7-7740X60

Adequate for light VM workloads, but limited core count and memory channels make it less suitable for heavy virtualization.

Efficiency

Core i5-7640X

14nm process and 112W TDP for a 4-core chip result in poor efficiency compared to mainstream alternatives.

Intel Core i7-7740X62

112 W TDP for a quad-core results in higher power draw per core than many modern designs.

Specialized Performance

AI / ML

Core i5-7640XPoor
  • No dedicated AI hardware
  • Low core count limits CPU-based inference
Intel Core i7-7740XLimited
  • No dedicated AI acceleration hardware
  • Suited only for CPU-bound inference and older ML frameworks

Content Creation

Core i5-7640XFair
Basic Photo EditingAudio Production
Intel Core i7-7740XAdequate
Light Photo EditingOccasional Video EditingBasic 3DCode Compilation

Gaming

Core i5-7640XGood
  • High clock speeds benefit high-refresh-rate gaming
  • 4 cores struggle with modern CPU-intensive titles
  • Requires a dedicated GPU
Intel Core i7-7740XVery Good
  • Strong single-threaded core performance keeps frame rates competitive in many titles
  • Best paired with mid-to-high-end discrete GPUs
  • Modern gaming CPUs with more cores and faster memory often deliver better 1% lows

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
1080p/1440p Gaming
Very Good
Enthusiast Overclocking
Good
Legacy X299 Reuse
Good
General Productivity
Adequate
Heavy Multi-threaded Workloads
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
Intel Core i7-7740X

Pros

  • High out-of-box clocks
  • Unlocked for overclocking
  • X299 platform offers flexible chipset PCIe lanes and storage options
  • Strong single-threaded performance for its era
  • Can breathe life into idle LGA2066 boards

Cons

  • Quad core count limits multi-threaded performance
  • Only 16 CPU PCIe lanes
  • No integrated graphics
  • 112 W TDP for four cores is relatively power-hungry
  • Platform is discontinued with limited future upgrade options

Competitors & Alternatives

Core i5-7640X

Intel Core i7-7740X

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

A niche, high-clock quad-core for X299 that delivers strong single-threaded performance but lacks the PCIe and memory bandwidth of Skylake-X siblings, making sense only at low prices for specific reuse scenarios.

Best for: Reusing an existing LGA2066 board for gaming or general tasks when the CPU is acquired at very low cost.

Read the full review

Frequently Asked Questions

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

Based on our editorial ratings, the Intel Core i7-7740X comes out ahead with a score of 7/10. 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, Core i5-7640X or Intel Core i7-7740X?

For gaming, the Intel Core i7-7740X leads with a gaming performance score of 78/100 among Core i5-7640X and Intel Core i7-7740X.

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

No. They use different sockets (Core i5-7640X: LGA 2066, Intel Core i7-7740X: LGA2066), so each needs a compatible motherboard.