CPU Comparison
Intel Core i9-7900X vs Intel Core i9-7940X
A side-by-side comparison of specs, performance and value. The Intel Core i9-7900X is a 10-core, 20-thread high-end desktop processor based on the Skylake-X architecture, targeting enthusiasts, content creators, and workstation users who need more cores, memory bandwidth, and PCIe lanes than mainstream desktop platforms offer.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Strong multi-threaded performance for creator workloads; competitive with or better than many mainstream 8–10 core CPUs at the time, though newer designs are faster per clock.
Solid multi-threaded performance for its era, though surpassed by modern 12 to 14-core mainstream parts.
Gaming
Capable of high-refresh-rate gaming at 1440p and above, but modern gaming-focused CPUs often deliver better minimums and efficiency.
Capable of high-refresh 1080p gaming, but newer mainstream CPUs deliver better frame rates and 1% lows.
Virtualization
Excellent for running multiple VMs thanks to 10 cores, 20 threads, and quad-channel memory, especially when paired with VT-x and VT-d support.
Great for home labs and multiple VMs thanks to 14 cores and quad-channel memory.
Efficiency
High power consumption and heat output compared to modern 10nm/7nm parts; requires robust cooling and a strong PSU.
Very poor efficiency compared to modern architectures, running hot and drawing significant power under load.
Specialized Performance
AI / ML
- No dedicated AI acceleration hardware like NPU or AI instructions beyond AVX-512.
- Suitable for CPU-based inference and small model workloads, but not competitive with modern AI-focused CPUs or GPUs.
- 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
- Strong single-core clocks up to 4.3–4.5 GHz enable high FPS in CPU-heavy titles.
- Most games don’t scale beyond 6–8 cores, so newer 8-core CPUs often match or beat it in gaming while using less power.
- Best suited for GPU-bound scenarios at 1440p/4K where the CPU is less of a bottleneck.
- 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
- 10 cores and 20 threads for heavy multi-threaded workloads.
- 44 PCIe 3.0 lanes from the CPU for multi-GPU and NVMe SSDs.
- Quad-channel DDR4-2666 with up to 85 GB/s bandwidth.
- Strong performance for content creation and virtualization at its price point.
- Unlocked multiplier for enthusiast overclocking.
- Turbo Boost Max 3.0 boosts up to 4.5 GHz on best cores.
Cons
- High 140W TDP and real-world power draw under load.
- 14nm process is significantly less efficient than modern 10nm/7nm designs.
- No integrated graphics; requires a discrete GPU.
- X299 platform is discontinued with no upgrade path beyond LGA2066.
- Mesh interconnect can increase lightly-threaded latency versus older ring-bus designs in some workloads.
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 i9-7900X
- AMD Ryzen Threadripper 1900XRival
High-End Desktop / Workstation
- AMD Ryzen 7 1800XRival
Mainstream High-End Desktop
- Compare head-to-headIntel Core i7-6950XRival
Previous-Gen HEDT
- Intel Core i9-7820XRival
8-Core HEDT Alternative
- Compare head-to-headIntel Core i9-7960XRival
Higher-Core-Count HEDT
Same platform with higher clocks and slightly better efficiency; better choice if staying on X299.
Compare head-to-head- AMD Ryzen 9 3900XAlt
Newer 12-core AM4 part with much better efficiency and strong creator performance; requires a new platform.
Modern 20-thread mainstream CPU with much better single-threaded and gaming performance, plus DDR5 support.
Compare head-to-head- AMD Ryzen 9 7900Alt
Efficient 12-core AM5 CPU with modern I/O (DDR5, PCIe 5.0) and far better power efficiency.
Later 12-core X-Series part on the same X299 platform if you want more cores but stay on LGA2066.
Compare head-to-head
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 once-flagship HEDT CPU that still delivers strong multi-threaded performance and I/O capability, but its 14nm process, high power draw, and discontinued platform make it mainly interesting for used builds or legacy systems.
Best for: Used workstation or creator build on X299 where multi-threaded performance and I/O matter more than efficiency or platform longevity.
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 i9-7900X or Intel Core i9-7940X?
Based on our editorial ratings, the Intel Core i9-7900X comes out ahead with a score of 8/10. 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 i9-7900X or Intel Core i9-7940X?
For gaming, the Intel Core i9-7900X leads with a gaming performance score of 78/100 among Intel Core i9-7900X and Intel Core i9-7940X.
Which uses less power?
The Intel Core i9-7900X has the lowest rated TDP. Power draw across these chips: Intel Core i9-7900X (140 W), Intel Core i9-7940X (165 W).
Do Intel Core i9-7900X and Intel Core i9-7940X use the same socket?
No. They use different sockets (Intel Core i9-7900X: LGA2066, 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 i9-7900X (10 cores), Intel Core i9-7940X (14 cores).
Which is faster in multi-core benchmarks?
The Intel Core i9-7900X posts the highest multi-core benchmark score. Multi-core results: Intel Core i9-7900X (10,199). Benchmark figures are approximate and workload-dependent.