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Intel Core i9-7940X X-series

Intel Core i9-7940X X-series: Comprehensive Review of the 2025 Processor

Architecture, Performance, and Relevance in the Era of New Technologies

1. Key Features: The Power of Skylake-X

The Intel Core i9-7940X processor, released in 2017, remains a niche solution for professionals even in 2025. Its Skylake-X architecture is built on a 14nm process, which, by modern standards, falls short of AMD's and Intel's 7nm and 5nm chips. However, with 14 cores and 28 threads (base clock 3.1GHz, turbo up to 4.4GHz), it delivers high multi-threaded performance.

Key Features:

- Support for AVX-512 for accelerated scientific calculations and rendering.

- 19.25 MB of cache (L3).

- 44 PCIe 3.0 lanes (compared to PCIe 5.0 in new CPUs).

- Unlocked multiplier for overclocking.

Performance:

- Geekbench 6: 1333 (Single-Core), 9537 (Multi-Core).

- In multi-threaded tasks (e.g., rendering in Blender), it outperforms many 8-core CPUs from 2023-2024, but lags behind modern Ryzen 9 7950X3D (16 cores, Geekbench Multi-Core ~24,000).

2. Compatible Motherboards: The LGA 2066 Platform

The processor utilizes the LGA 2066 socket and X299 chipset, limiting the selection of motherboards. In 2025, new boards are rare, but several models are available on the secondary market:

- ASUS ROG Rampage VI Extreme (used price: $200–$300).

- MSI X299 Gaming Pro Carbon AC (used price: $150–$250).

- Gigabyte X299 AORUS Ultra Gaming (used price: $180–$270).

Selection Considerations:

- Ensure support for DDR4-2666 MHz (officially) and memory overclocking capability.

- For CPU overclocking, a motherboard with a reliable VRM (e.g., 8+ power phases) is essential.

- Check for necessary ports (USB 3.1 Gen2, Thunderbolt 3 via additional controllers).

3. Memory: Quad-Channel DDR4

The i9-7940X supports quad-channel DDR4 with a maximum capacity of 128GB (up to 3600 MHz when overclocked). Recommended configurations:

- 4×16GB DDR4-3200 (optimal for rendering).

- 8×8GB DDR4-3600 (maximum bandwidth).

Important: DDR5 is not supported. For tasks requiring high memory speeds (e.g., AI modeling), this is a significant drawback.

4. Power Supply: Minimum 750W

With a TDP of 165W and peak consumption up to 300W (when overclocked), a power supply with headroom is necessary:

- Minimum: 750W (e.g., Corsair RM750x).

- Recommended: 850–1000W (Seasonic PRIME TX-850, Be Quiet! Dark Power 12).

Tip: Use a power supply with an 80+ Gold/Platinum certification and separate 8+4 pin cables for the CPU.

5. Pros and Cons

Pros:

- 14 cores for $400–$600 (new stock in 2025).

- Good overclocking potential.

- Suitable for workstations.

Cons:

- High power consumption and heat generation.

- Lacks PCIe 4.0/5.0 and DDR5 support.

- Outdated architecture compared to Zen 4/5 and 13th generation Intel.

6. Use Cases

- Work Tasks: Video editing (Premiere Pro), 3D rendering (V-Ray), code compilation.

- Gaming: Not the best choice — in Full HD, it lags behind the Ryzen 5 7600X due to lower IPC. However, in 4K with RTX 4090, the gap narrows.

- Multimedia: Streaming + encoding without lags.

Practical Example: Editor Alexey uses the i9-7940X with 64GB DDR4 and RTX 4080 for rendering 8K video. He claims the CPU performs at the level of the Ryzen 9 7900X, but gets hotter.

7. Comparison with Competitors

- AMD Threadripper 1920X (12 cores): Cheaper ($250 used), but weaker in multi-threaded performance (Geekbench Multi-Core ~7000).

- Intel Core i9-13900K (24 cores): 30% faster in Single-Core, supports DDR5 and PCIe 5.0 (new price: $550).

- Ryzen 9 7950X (16 cores): Multi-Core ~24,000 in Geekbench 6, but more expensive ($600–$700).

Conclusion: The i9-7940X is relevant only with a budget of up to $500 and the need for multi-threading without upgrading the platform.

8. Building Tips

- Cooling: A liquid cooling solution (e.g., Arctic Liquid Freezer II 360) or a top-tier air cooler (Noctua NH-D15) is necessary.

- Case: At least 6 fans for ventilation.

- Motherboard: Look for models with VRM heatsinks and BIOS updates from 2022+.

- SSD: Use NVMe PCIe 3.0 (Samsung 970 Evo Plus) — faster than SATA but without the premium for PCIe 4.0.

9. Conclusion: Who Should Consider the i9-7940X in 2025?

This processor is worth considering for:

- Professionals on a budget who need many cores for rendering.

- Enthusiasts willing to experiment with overclocking on an outdated platform.

- Owners of X299 systems looking to upgrade without changing the motherboard.

Alternative: If modern technologies (DDR5, PCIe 5.0) are needed, it’s better to choose Ryzen 9 7900X or Intel Core i7-14700K.

Final Verdict: The Intel Core i9-7940X is a "workhorse" for specific tasks, but not for gaming or future upgrades. Its main advantage in 2025 is its price on the secondary market and proven reliability.

Basic

Label Name

Intel

Platform

Desktop

Launch Date

July 2017

Model Name

The Intel processor number is just one of several factors - along with processor brand, system configurations, and system-level benchmarks - to be considered when choosing the right processor for your computing needs.

i9-7940X

Code Name

SkyLake

CPU Specifications

Total Cores

Cores is a hardware term that describes the number of independent central processing units in a single computing component (die or chip).

Total Threads

Where applicable, Intel® Hyper-Threading Technology is only available on Performance-cores.

Basic Frequency

3.10 GHz

Max Turbo Frequency

Max Turbo Frequency is the maximum single-core frequency at which the processor is capable of operating using Intel® Turbo Boost Technology and, if present, Intel® Turbo Boost Max Technology 3.0 and Intel® Thermal Velocity Boost. Frequency is typically measured in gigahertz (GHz), or billion cycles per second.

4.30 GHz

Intel Hyper-Threading Technology

Intel® Hyper-Threading Technology (Intel® HT Technology) delivers two processing threads per physical core. Highly threaded applications can get more work done in parallel, completing tasks sooner.

Yes

Intel Turbo Boost Technology

Intel® Turbo Boost Technology dynamically increases the processor's frequency as needed by taking advantage of thermal and power headroom to give you a burst of speed when you need it, and increased energy efficiency when you don’t.

2.0

Intel Turbo Boost Max Technology 3.0 Frequency

Intel® Turbo Boost Max Technology 3.0 identifies the best performing core(s) on a processor and provides increased performance on those cores through increasing frequency as needed by taking advantage of power and thermal headroom. Intel® Turbo Boost Max Technology 3.0 frequency is the clock frequency of the CPU when running in this mode.

4.40 GHz

Intel Turbo Boost Max Technology 3.0

Yes

CPU Socket

The socket is the component that provides the mechanical and electrical connections between the processor and motherboard.

FCLGA2066

TDP

165 W

Max. Operating Temperature

Junction Temperature is the maximum temperature allowed at the processor die.

102°C

PCI Express Version

PCI Express Revision is the supported version of the PCI Express standard. Peripheral Component Interconnect Express (or PCIe) is a high-speed serial computer expansion bus standard for attaching hardware devices to a computer. The different PCI Express versions support different data rates.

3.0

Number of PCI Express Lanes

A PCI Express (PCIe) lane consists of two differential signaling pairs, one for receiving data, one for transmitting data, and is the basic unit of the PCIe bus. Max # of PCI Express Lanes is the total number of supported lanes.

Intel 64

Intel® 64 architecture delivers 64-bit computing on server, workstation, desktop and mobile platforms when combined with supporting software.¹ Intel 64 architecture improves performance by allowing systems to address more than 4 GB of both virtual and physical memory.

Yes

Memory Specifications

Memory Type

Intel® processors come in four different types: Single Channel, Dual Channel, Triple Channel, and Flex Mode. Maximum supported memory speed may be lower when populating multiple DIMMs per channel on products that support multiple memory channels.

DDR4-2666

Max Memory Size

Max memory size refers to the maximum memory capacity supported by the processor.

128 GB

Memory Channels

The number of memory channels refers to the bandwidth operation for real world application.

Max Memory Bandwidth

Max Memory bandwidth is the maximum rate at which data can be read from or stored into a semiconductor memory by the processor (in GB/s).

85 GB/s

Bus Speed

8 GT/s

ECC Memory Supported

ECC Memory Supported indicates processor support for Error-Correcting Code memory. ECC memory is a type of system memory that can detect and correct common kinds of internal data corruption. Note that ECC memory support requires both processor and chipset support.

Miscellaneous

Intel Virtualization Technology for Directed I/O (VT-d)

Intel® Virtualization Technology for Directed I/O (VT-d) continues from the existing support for IA-32 (VT-x) and Itanium® processor (VT-i) virtualization adding new support for I/O-device virtualization. Intel VT-d can help end users improve security and reliability of the systems and also improve performance of I/O devices in virtualized environments.

Yes

Intel Virtualization Technology (VT-x)

Intel® Virtualization Technology (VT-x) allows one hardware platform to function as multiple “virtual” platforms. It offers improved manageability by limiting downtime and maintaining productivity by isolating computing activities into separate partitions.

Yes

Intel Standard Manageability (ISM)

Intel® Standard Manageability is the manageability solution for Intel vPro® Essentials platforms and is a subset of Intel® AMT with out-of-band management over Ethernet and Wi-Fi, but no KVM or new life cycle management features.

Intel® SSE4.1 | Intel® SSE4.2 | Intel® AVX2 | Intel® AVX-512

Number of AVX-512 FMA Units

Enhanced Intel SpeedStep Technology

Enhanced Intel SpeedStep® Technology is an advanced means of enabling high performance while meeting the power-conservation needs of mobile systems. Conventional Intel SpeedStep® Technology switches both voltage and frequency in tandem between high and low levels in response to processor load. Enhanced Intel SpeedStep® Technology builds upon that architecture using design strategies such as Separation between Voltage and Frequency Changes, and Clock Partitioning and Recovery.

Yes

Execute Disable Bit

Execute Disable Bit is a hardware-based security feature that can reduce exposure to viruses and malicious-code attacks and prevent harmful software from executing and propagating on the server or network.

Yes

Cache

CPU Cache is an area of fast memory located on the processor. Intel® Smart Cache refers to the architecture that allows all cores to dynamically share access to the last level cache.

19.25 MB

Intel AES New Instructions

Intel® AES New Instructions (Intel® AES-NI) are a set of instructions that enable fast and secure data encryption and decryption. AES-NI are valuable for a wide range of cryptographic applications, for example: applications that perform bulk encryption/decryption, authentication, random number generation, and authenticated encryption.

Yes

Benchmarks

Geekbench 6

Single Core Score

1333

Geekbench 6

Multi Core Score

9537

Geekbench 5

Single Core Score

1068

Geekbench 5

Multi Core Score

11414

Compared to Other CPU

Geekbench 6 Single Core

Xeon W-3235

1414 +6.1%

Xeon W-2195

1372 +2.9%

Core i9-7940X X-series

1333

Ryzen 5 5500U

1287 -3.5%

Xeon E3-1225 v6

1252 -6.1%

Geekbench 6 Multi Core

Ryzen 9 7940H

11069 +16.1%

Core Ultra 7 266V

10237 +7.3%

Core i9-7940X X-series

9537

Core i9-13905H

8948 -6.2%

Core i9-7900X

8536 -10.5%

Geekbench 5 Single Core

Xeon Silver 4309Y

1113 +4.2%

Xeon Gold 5220T

1089 +2%

Core i9-7940X X-series

1068

Core i5-9400F

1044 -2.2%

Ryzen 5 5500U

1022 -4.3%

Geekbench 5 Multi Core

Xeon Gold 5415+

13908 +21.9%

M1 Max

12511 +9.6%

Core i9-7940X X-series

11414

Xeon Gold 6208U

10547 -7.6%

Ryzen Threadripper 2920X

9818 -14%