CPU Comparison

Core i7-7700K vs Core i7-7740X

A side-by-side comparison of specs, performance and value. The Intel Core i7-7700K is a high-performance desktop processor launched in January 2017, representing the flagship of the Kaby Lake mainstream lineup. Built on the 14nm+ process, this quad-core CPU features Hyper-Threading, delivering 8 concurrent threads. It operates at an aggressive base clock of 4.2 GHz and boosts up to 4.5 GHz out of the box, providing exceptional single-threaded performance. The K suffix denotes an unlocked multiplier, making it a favorite among enthusiasts for overclocking, often pushing beyond 5.0 GHz with adequate cooling. With a 91W TDP, it demands robust cooling, especially since it uses thermal paste instead of solder between the die and IHS, a point of criticism among the community. It features 8MB of L3 cache and supports dual-channel DDR4-2400 memory. The integrated Intel HD Graphics 630 offers basic display capabilities, though its primary market is gamers relying on discrete GPUs. The i7-7700K marked the pinnacle of Intel's quad-core dominance before market pressures forced a core count increase.

Top pick
Intel · 7th Generation Core i7
Core i7-7700K
4C / 8T4.5 GHz91 W
7.5
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
Performance Desktop
High-End Desktop
Generation
7th Gen
7th Gen X-Series
Launched
2017
2017
Status
Active
Active
Codename
Kaby Lake
Kaby Lake-X
Series
7th Generation Core i7
X-Series 7th Gen
Family
Kaby Lake
Kaby Lake-X
Predecessor
Core i7-6700K
Core i7-6700K
Successor
Core i7-8700K
N/A

Specifications Compared

Cores & Clocks
Cores
4
4
Threads
8
8
Base Clock
4.2 GHz
4.3 GHz
Boost Clock
4.5 GHz
4.6 GHz
Cache & Power
L3 Cache
8 MB
8 MB
TDP
91 W
112 W
Architecture
Architecture
Kaby Lake
Kaby Lake-X
Process Node
14nm
14nm
Memory
Memory Type
DDR4
DDR4
Memory Speed
2400 MT/s
2666 MT/s
Memory Channels
Dual (2)
Dual (2)
Max Memory
64 GB
128 GB
Platform & I/O
Socket
LGA 1151
LGA 2066
PCIe Version
PCIe 3.0
PCIe 3.0
PCIe Lanes
16
16
Integrated GPU
Yes
None
Unlocked
Yes
Yes

Industry Impact

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

Best CPU by Use Case

Competitive Gaming
Very Good
Overclocking
Excellent
Extreme Overclocking
Very Good
General Workstation
Poor

Target Audience

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

Strengths & Weaknesses

Core i7-7700K

Pros

  • Excellent single-core performance
  • Unlocked for overclocking
  • Easily hits 5.0 GHz with AIO cooling
  • Great for high-refresh-rate 1080p gaming

Cons

  • Only 4 cores
  • Uses thermal paste instead of solder (runs hot)
  • High power draw when overclocked
  • LGA 1151 is a dead platform
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 i7-7700K

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 i7-7700KSituational

A legendary overclocker that delivered top-tier single-core performance in 2017, but its 4-core limit shows its age in modern multi-threaded workloads.

Best for: Upgrading an existing Z270 system cheaply

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 i7-7700K or Core i7-7740X?

Based on our editorial ratings, the Core i7-7700K 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 uses less power?

The Core i7-7700K has the lowest rated TDP. Power draw across these chips: Core i7-7700K (91 W), Core i7-7740X (112 W).

Do Core i7-7700K and Core i7-7740X use the same socket?

No. They use different sockets (Core i7-7700K: LGA 1151, Core i7-7740X: LGA 2066), so each needs a compatible motherboard.