CPU Comparison
Intel Core i9-7920X vs Intel Core i9-7940X
A side-by-side comparison of specs, performance and value. The Intel Core i9-7920X is a 12-core, 24-thread high-end desktop processor from the Skylake-X generation on LGA2066, featuring 44 PCIe 3.0 lanes, quad-channel DDR4-2666, and AVX-512 support. It launched in August 2017 at $1,199 and is now discontinued, positioning it as a legacy option for multi-threaded workloads and enthusiast platforms that need abundant I/O. Despite its age, it retains value for specific upgrade scenarios where the X299 platform and expansion are priorities, though modern CPUs deliver far better efficiency and per-thread performance.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Strong multi-threaded performance for its era; still usable for rendering and encoding if power and platform age are acceptable.
Solid multi-threaded performance for its era, though surpassed by modern 12 to 14-core mainstream parts.
Gaming
Acceptable frame rates in many titles, but modern gaming CPUs with higher clocks and newer architectures will outpace it.
Capable of high-refresh 1080p gaming, but newer mainstream CPUs deliver better frame rates and 1% lows.
Virtualization
Plenty of cores, threads, and PCIe lanes make it a solid choice for multiple VMs and storage devices.
Great for home labs and multiple VMs thanks to 14 cores and quad-channel memory.
Efficiency
At 14 nm and 140 W base TDP, the 7920X draws significantly more power per unit of performance than newer parts.
Very poor efficiency compared to modern architectures, running hot and drawing significant power under load.
Specialized Performance
AI / ML
- No dedicated AI accelerators; AI workloads rely on AVX-512 and general-purpose compute.
- Useful for small-scale inference prototyping or running traditional ML workloads on CPU.
- AVX-512 helps with some vector calculations
- No dedicated AI acceleration hardware
- CPU-based inference is significantly slower than modern NPUs or GPUs
Content Creation
Gaming
- Single-core Turbo Boost Max 3.0 up to 4.4 GHz helps in CPU-limited titles.
- Lacks the high clocks and IPC gains of newer CPUs, so GPU-heavy games at high resolutions are the best fit.
- PCIe 3.0 is adequate for current GPUs, though Gen4/Gen5 offer more headroom for fast NVMe and future cards.
- High clock speeds help push frames in CPU-bound scenarios
- Mesh architecture adds slight latency compared to ring bus designs
- Lacks the cache size and IPC of modern gaming CPUs
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- 12 cores and 24 threads for heavily threaded workloads.
- 44 PCIe 3.0 lanes for multi-GPU and NVMe configurations.
- Quad-channel DDR4-2666 with up to 128 GB capacity.
- AVX-512 support with 2 FMA units for vectorized compute.
- Unlocked multiplier for enthusiast tuning.
Cons
- Discontinued platform with no upgrade path beyond Cascade Lake-X refresh.
- Higher power consumption and heat compared to newer architectures.
- Base clock is modest at 2.9 GHz; all-core boost is 4.3 GHz.
- No integrated graphics; requires a discrete GPU.
- Lacks modern platform features (DDR5, PCIe 4.0+).
Pros
- 14 cores and 28 threads
- 44 PCIe 3.0 lanes for expansive I/O
- Quad-channel DDR4 memory support
- AVX-512 instruction support
- Unlocked multiplier for overclocking
Cons
- Runs extremely hot under heavy loads
- High power consumption for the performance delivered
- Lacks integrated graphics
- Discontinued and outdated platform
- Outpaced by modern mainstream CPUs in efficiency and IPC
Competitors & Alternatives
Intel Core i9-7920X
- AMD Ryzen Threadripper 1920XRival
HEDT
- AMD Ryzen 9 5900XRival
Mainstream Enthusiast
- Compare head-to-headAMD Ryzen 9 7900XRival
Mainstream Enthusiast
- RivalCompare head-to-head
- Compare head-to-headIntel Core i7-14700KRival
Mainstream Enthusiast
Intel Core i9-7940X
- AMD Ryzen Threadripper 1950XRival
Workstation
- AMD Ryzen Threadripper 1920XRival
Workstation
- Compare head-to-headIntel Core i9-7960XRival
High-End Desktop
- Compare head-to-headIntel Core i9-7900XRival
High-End Desktop
- Compare head-to-headIntel Core i7-7820XRival
High-End Desktop
Newer Cascade Lake-X alternative on the same platform with better value and refined behavior.
Compare head-to-head- AMD Ryzen 9 5900XAlt
Much more efficient, faster single-core, and relies on a modern AM4 platform.
Massively faster single-core and multi-core performance with modern features at a lower power draw.
Compare head-to-headModern platform with DDR5 and PCIe 5.0, offering vastly superior efficiency.
Compare head-to-headTop-tier modern performance for any workload, leaving the 7940X far behind.
Compare head-to-head
Our Verdict on Each
A capable 12-core HEDT chip with strong multi-threaded throughput and excellent I/O, but high power draw, an aging platform, and discontinued status make it relevant mainly for used-market upgrades or extending existing X299 builds.
Best for: Upgrading an existing X299 system at low cost (used CPU) to gain cores and PCIe lanes without replacing motherboard and memory.
Read the full reviewA potent HEDT processor for its time, the i9-7940X offers strong multi-core capabilities but suffers from high heat output and is outpaced by modern mainstream chips.
Best for: Upgrading an existing LGA 2066 workstation on a tight budget.
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i9-7920X or Intel Core i9-7940X?
Based on our editorial ratings, the Intel Core i9-7940X 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 is faster for gaming, Intel Core i9-7920X or Intel Core i9-7940X?
For gaming, the Intel Core i9-7940X leads with a gaming performance score of 75/100 among Intel Core i9-7920X and Intel Core i9-7940X.
Which uses less power?
The Intel Core i9-7920X has the lowest rated TDP. Power draw across these chips: Intel Core i9-7920X (140 W), Intel Core i9-7940X (165 W).
Do Intel Core i9-7920X and Intel Core i9-7940X use the same socket?
No. They use different sockets (Intel Core i9-7920X: LGA2066 (FCLGA2066), Intel Core i9-7940X: LGA 2066), so each needs a compatible motherboard.
Which has more cores?
The Intel Core i9-7940X has the most cores. Core counts: Intel Core i9-7920X (12 cores), Intel Core i9-7940X (14 cores).