CPU Comparison
Intel Core i7-4940MX vs Core i7-3940XM
A side-by-side comparison of specs, performance and value. The Intel Core i7-4940MX is an extreme edition mobile processor released in early 2014 as the absolute top-end of the Haswell mobile lineup. Designed for the most powerful gaming and workstation laptops, it features four cores and eight threads. Like its predecessor, it boasts an unlocked multiplier for enthusiast overclocking. It operates at a base clock of 3.1 GHz and can turbo boost up to 4.0 GHz, a significant milestone for mobile CPUs at the time. It includes a full 8 MB of L3 SmartCache and carries a 57-watt thermal design power. The integrated Intel HD 4600 graphics are present, though such systems invariably use discrete GPUs. This CPU was the ultimate mobile processor for 2014, catering to a niche audience of hardcore enthusiasts willing to pay a premium for unlocked mobile overclocking and maximum multi-threaded performance.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
8 threads and 4.0 GHz boost make quick work of compiling and rendering.
High clocks keep it surprisingly snappy for basic tasks.
Gaming
Excellent for older games and can handle modern eSports easily with a discrete GPU.
Excellent for 2012 games, can still handle older esports titles.
Virtualization
Good for running VMs, though limited by mobile platform constraints.
Great for running VMs on the go.
Efficiency
57W TDP is very power-hungry for a mobile chip, resulting in poor battery life.
55W TDP is terrible for battery life.
Specialized Performance
AI / ML
- No AI hardware
- CPU inference is slow
- No modern AI support
- Instruction sets outdated
Content Creation
Gaming
- Won't bottleneck 2014-era GPUs
- Can be overclocked for extra FPS
- Requires massive laptop cooling
- Max Ivy Bridge single-core speed
- Needs discrete GPU
- Overclockable for extra headroom
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- 4.0 GHz turbo boost
- Unlocked multiplier
- Full 8MB L3 cache
- Removable PGA socket
Cons
- Extremely high 57W TDP
- Runs very hot
- Expensive launch price
- Poor battery life
Pros
- Unlocked multiplier for extreme overclocking
- Highest Ivy Bridge mobile clocks
- Socketed for upgrades
- Excellent 2012 performance
Cons
- Extremely high 55W TDP
- Runs very hot
- Lacks AVX2
- Massive power draw for mobile
Competitors & Alternatives
Intel Core i7-4940MX
- AMD A10-5750MRival
Mobile
- Compare head-to-headIntel Core i7-4900MQRival
Mobile
- Compare head-to-headIntel Core i7-4930MXRival
Mobile Extreme
- Intel Core i7-3940XMRival
Mobile Extreme
- AMD FX-7600PRival
Mobile
- Intel Core i7-5950HQAlt
Newer Broadwell architecture with better efficiency.
- AMD Ryzen 7 3750HAlt
Modern mobile alternative with better efficiency.
6-core modern alternative that destroys it in performance.
Compare head-to-head- Alt
Incredible modern performance per watt.
Compare head-to-head
Core i7-3940XM
- AMD A10-4600MRival
Mobile
- Intel Core i7-3920XMAlt
Slightly slower but essentially the same chip.
The newer Haswell-based Extreme Edition.
Compare head-to-head
Our Verdict on Each
A legendary mobile CPU that hit 4.0 GHz and offered unlocked overclocking, providing desktop-level performance for laptops.
Best for: Collecting vintage gaming laptops or extreme budget used systems.
Read the full reviewA minor but potent refresh of the 3920XM, offering the absolute best Ivy Bridge mobile performance with unlocked overclocking potential.
Best for: Maxing out an old extreme gaming laptop.
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i7-4940MX or Core i7-3940XM?
Based on our editorial ratings, the Core i7-3940XM comes out ahead with a score of 8.2/10. 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 i7-3940XM has the lowest rated TDP. Power draw across these chips: Intel Core i7-4940MX (57 W), Core i7-3940XM (55 W).
Do Intel Core i7-4940MX and Core i7-3940XM use the same socket?
No. They use different sockets (Intel Core i7-4940MX: Intel Socket G3, Core i7-3940XM: Intel Socket G2 (988B)), so each needs a compatible motherboard.
Which is faster in multi-core benchmarks?
The Core i7-3940XM posts the highest multi-core benchmark score. Multi-core results: Intel Core i7-4940MX (6,200), Core i7-3940XM (9,200). Benchmark figures are approximate and workload-dependent.