Quick Verdict
A minor but potent refresh of the 3920XM, offering the absolute best Ivy Bridge mobile performance with unlocked overclocking potential.
Overview
Launch
2012
Status
End-of-lifeGeneration
3rd Generation
Market
Mobile
The Intel Core i7-3940XM Extreme Edition is a high-end mobile processor released in September 2012 as a minor refresh to the 3920XM. Built on the 22nm Ivy Bridge architecture, it features 4 cores, 8 threads, and an unlocked multiplier for enthusiast overclocking. The primary upgrade is a slight bump in base frequency to 3.0 GHz, with turbo boost reaching up to 3.9 GHz. It retains the 55W TDP, 8MB of L3 cache, and Socket G2 (988B) compatibility. This processor was designed for the most demanding mobile workstations and gaming laptops, offering desktop-class tunability. The 3940XM represents the absolute peak of the Ivy Bridge mobile lineup, providing the highest clock speeds available before the transition to the Haswell architecture. It includes Intel HD 4000 graphics, though it was almost always paired with high-end discrete GPUs in the thick, heavy laptops it inhabited.
The Core i7-3940XM pushes Ivy Bridge to its limits with a 3.0 GHz base and 3.9 GHz turbo.
Its 55W TDP and unlocked multiplier make it a powerhouse for heavy mobile workstations, delivering top-tier 2012 performance and tuning capabilities.
Specifications
Performance
High clocks keep it surprisingly snappy for basic tasks.
Great for running VMs on the go.
Excellent for 2012 games, can still handle older esports titles.
55W TDP is terrible for battery life.
- •Max Ivy Bridge single-core speed
- •Needs discrete GPU
- •Overclockable for extra headroom
- •No modern AI support
- •Instruction sets outdated
Architecture
22nm
Process Node
Ivy Bridge
Codename
4C / 8T
Core Config
8 MB
L3 Cache
55 W
TDP
Architecture Overview
The Core i7-3940XM is the pinnacle of Intel's Ivy Bridge mobile architecture. It utilizes the same 22nm Tri-Gate process and Socket G2 (988B) as the rest of the lineup. The key difference lies in the binning; this chip is selected for its ability to sustain a 3.0 GHz base clock and 3.9 GHz turbo within a 55W thermal envelope. The unlocked multiplier allows users to push beyond these limits, provided the laptop's cooling can handle it. The architecture supports 8 threads via Hyper-Threading across 4 physical cores, with 8MB of shared L3 cache. Dual-channel DDR3-1600 memory support ensures ample bandwidth, and 16 lanes of PCIe 3.0 allow for full-speed connection to high-end discrete GPUs. The integrated HD 4000 graphics feature a dynamic clock of 650-1300 MHz. This CPU was designed to extract every last drop of performance from the Ivy Bridge architecture before Haswell arrived.
CPU Design
4 cores, 8 threads, unlocked multiplier.
Memory Subsystem
Dual-channel DDR3-1600.
PCIe & I/O
16 lanes of PCIe 3.0.
Overclocking
Fully unlocked for multiplier tuning.
- 100 MHz higher base clock
- 100 MHz higher turbo clock
Key Highlights
- Unlocked multiplier for extreme overclocking
- Highest Ivy Bridge mobile clocks
- Socketed for upgrades
- Excellent 2012 performance
- Extremely high 55W TDP
- Runs very hot
- Lacks AVX2
- Massive power draw for mobile
History
The Core i7-3940XM launched on September 3, 2012, as a refresh to keep Intel's mobile lineup competitive before the Haswell architecture arrived in 2013. It was a simple binning exercise, taking the 3920XM and bumping the clocks by 100 MHz. At the time, it was the fastest mobile CPU money could buy, found only in the most expensive gaming laptops from brands like Origin, Maingear, and Alienware.
It catered to a very small niche of users who wanted desktop-level overclocking in a portable form factor. The 3940XM marked the end of the Ivy Bridge era for mobile. It was the last hurrah for the Socket G2 Extreme Editions before Intel shifted to a new socket and the Haswell architecture.
Today, it is a collector's item of sorts, representing a time when laptop CPUs were massive, power-hungry, and highly tunable.
Improvements over Previous Generation
- 100 MHz higher base clock
- 100 MHz higher turbo clock
Alternatives & Competitors
Should You Buy It?
Not Recommended for the right buyer
Maxing out an old extreme gaming laptop.
Avoid if…
- Buying a new laptop
- Need modern features
- Care about battery life
Use Cases
Interesting Facts
It is a minor refresh of the 3920XM.
Has a 3.0 GHz base clock.
Turbo boosts up to 3.9 GHz.
Features an unlocked multiplier.
Uses Socket G2 (988B).
TDP is 55W.
Has 8MB of L3 cache.
Built on 22nm process.
Launched in September 2012.
HD 4000 graphics clock up to 1300 MHz.
People Also Ask
Is the i7-3940XM unlocked?
Yes, it features an unlocked multiplier.
What is the TDP of the i7-3940XM?
It has a 55-watt TDP.
What is the base clock of the i7-3940XM?
The base clock is 3.0 GHz.
What socket does the i7-3940XM use?
It uses Socket G2 (988B).
Does the i7-3940XM have integrated graphics?
Yes, it has Intel HD 4000 graphics.
What is the max turbo of the i7-3940XM?
The max turbo is 3.9 GHz.
What generation is the i7-3940XM?
It is a 3rd Gen Ivy Bridge processor.
Can I overclock the i7-3940XM?
Yes, the multiplier is fully unlocked.
Does the i7-3940XM support PCIe 3.0?
Yes, it supports PCIe 3.0.
How many cores does it have?
It has 4 cores and 8 threads.
Frequently Asked Questions
What is the difference between 3920XM and 3940XM?
The 3940XM has a 100 MHz higher base and turbo clock.
Is it good for modern gaming?
No, it is too old for modern AAA games.
Does it support DDR4?
No, it supports DDR3.
What is the die size?
The die size is 160 mm².
Does it support AVX?
Yes, it supports AVX.
What is the max memory support?
It supports up to 32GB of DDR3.
Does it support virtualization?
Yes, it supports VT-x and VT-d.
How many transistors does it have?
It has 1.4 billion transistors.
Is it soldered?
No, it uses a PGA socket.
What package does it use?
It uses the FC-PGA12F package.