Quick Verdict
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.
Overview
Launch
2017
Status
DiscontinuedGeneration
7th Gen X-Series (Kaby Lake-X)
Market
Desktop
The Intel Core i7-7740X is a quad-core, eight-thread desktop processor from the Kaby Lake-X family, designed for the LGA2066 (X299) platform with 14 nm manufacturing, a base clock of 4.30 GHz, and a max turbo of 4.50 GHz.
The Core i7-7740X combines 4 cores, 8 threads, 4.3–4.5 GHz clocks, and DDR4-2666 dual-channel memory on LGA2066, but only provides 16 PCIe lanes from the CPU and lacks integrated graphics, making it a specialized choice for existing X299 owners or overclockers.
Specifications
Performance
Quad-core limits performance in heavily parallelized applications compared to higher core-count alternatives.
Adequate for light VM workloads, but limited core count and memory channels make it less suitable for heavy virtualization.
Paired with a strong discrete GPU, the high clocks enable smooth high-refresh gaming, though newer platforms offer better efficiency and future-proofing.
112 W TDP for a quad-core results in higher power draw per core than many modern designs.
- •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
- •No dedicated AI acceleration hardware
- •Suited only for CPU-bound inference and older ML frameworks
Architecture
14 nm
Process Node
Kaby Lake-X
Codename
4C / 8T
Core Config
8 MB
L3 Cache
112 W
TDP
Architecture Overview
Kaby Lake-X is a derivative of the mainstream Kaby Lake architecture adapted for the LGA2066 (X299) HEDT platform with four physical cores.
CPU Design
4 cores / 8 threads via Hyper-Threading, operating at high frequencies with an unlocked multiplier.
Memory Subsystem
Dual-channel DDR4 memory controller up to DDR4-2666, supporting up to 64 GB.
PCIe & I/O
16 PCIe 3.0 lanes directly from the CPU, plus additional lanes provided by the X299 chipset for expansion.
Overclocking
Unlocked multiplier designed for enthusiasts, supported by motherboards with robust VRM and cooling.
- Slightly higher base clock compared to i7-7700K
- Support for X299 platform and additional chipset PCIe lanes
- Higher overclocking headroom on many X299 boards
Key Highlights
- 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
- 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
History
The Core i7-7740X arrived in 2017 as part of Intel’s X299 launch, blending a quad-core Kaby Lake-X die with the high-end desktop LGA2066 platform. It offered a familiar 4C/8T configuration at higher clocks, targeting enthusiasts who already invested in X299 boards and valued single-threaded performance. Unlike Skylake-X, Kaby Lake-X models retained dual-channel memory and 16 CPU PCIe lanes, which created clear segmentation within the X-series lineup.
Today it stands as a niche option for repurposing X299 systems on a tight budget.
Improvements over Previous Generation
- Slightly higher base clock compared to i7-7700K
- Support for X299 platform and additional chipset PCIe lanes
- Higher overclocking headroom on many X299 boards
Alternatives & Competitors
Should You Buy It?
Not Recommended for the right buyer
Reusing an existing LGA2066 board for gaming or general tasks when the CPU is acquired at very low cost.
Avoid if…
- Building a new system from scratch
- Prioritizing multi-threaded productivity or workstation workloads
- Seeking strong upgrade path or long-term platform support
Use Cases
Interesting Facts
Kaby Lake-X quad-core models on LGA2066 use only two memory channels, unlike Skylake-X siblings which feature quad-channel memory.
Max memory bandwidth listed by Intel is 42 GB/s, consistent with dual-channel DDR4-2666 operation.
Intel ARK lists '0 QPI Links' and a Bus Speed of 8 GT/s for this processor.
The 8 MB Smart Cache size matches the mainstream i7-7700K, reflecting the shared lineage.
Intel ARK shows Intel Optane Memory Supported: Yes on this SKU.
Packaging thermal specification is PCG 2017X and TJUNCTION is 100°C.
Marketed as part of the X-series but with significantly fewer I/O resources than higher-end SKUs.
Boxed product does not include a stock cooler, requiring an aftermarket cooling solution.
Supports Intel VT-x and VT-d for virtualization.
End of Servicing Updates date on Intel ARK is March 31, 2024.
People Also Ask
Does the Intel Core i7-7740X have integrated graphics?
No, the i7-7740X does not include integrated graphics; a discrete GPU is required.
What socket does the Core i7-7740X use?
It uses the LGA2066 socket with the X299 chipset platform.
Is the i7-7740X unlocked?
Yes, it features an unlocked multiplier for enthusiast overclocking.
How many PCIe lanes does the i7-7740X have?
It provides 16 PCIe 3.0 lanes from the CPU, configurable as 1x16 or 2x8.
What memory does the i7-7740X support?
It supports up to DDR4-2666 memory in dual-channel configuration up to 64 GB.
What is the TDP of the i7-7740X?
The processor has a 112 W TDP.
Is the Intel Core i7-7740X still worth it in 2026?
Only at very low prices to repurpose an existing X299 board; new builds should prefer newer platforms.
Does the i7-7740X support quad-channel memory?
No, Kaby Lake-X supports dual-channel memory; quad-channel is exclusive to Skylake-X on X299.
What are the clock speeds of the i7-7740X?
Base clock is 4.30 GHz with a max turbo of 4.50 GHz.
Does the boxed i7-7740X include a cooler?
No, the boxed product does not include a stock cooling solution.
Frequently Asked Questions
Can I use DDR5 with the i7-7740X?
No, it supports DDR4 memory only.
Is ECC memory supported?
Intel ARK lists ECC Memory Supported: No.
What is the maximum memory capacity?
Up to 64 GB of DDR4-2666, dependent on the motherboard.
Does this CPU support Intel Optane Memory?
Intel ARK indicates Intel Optane Memory Supported: Yes.
What is the lithography process?
14 nm.
What is the cache size?
8 MB Smart Cache.
Does the i7-7740X support VT-x and VT-d?
Yes, Intel VT-x and Intel VT-d are supported.
Are AVX instructions supported?
Yes, it supports Intel SSE4.1, SSE4.2, and AVX2 extensions.
Is the i7-7740X still being manufactured?
No, Intel lists Marketing Status: Discontinued.
What is TJUNCTION for this CPU?
100°C.