CPU Comparison

Core i7-840QM vs Core i7-940XM

A side-by-side comparison of specs, performance and value. The Intel Core i7-840QM is a high-end mobile quad-core processor launched in June 2010. Based on the Clarksfield architecture, it features 4 cores and 8 threads with a base clock of 1.86 GHz and a turbo boost up to 3.2 GHz. With a 45W TDP, it was a premium offering for workstation and gaming laptops. Built on a 45nm process, it includes 8MB of L3 cache and supports dual-channel DDR3-1333 memory, but lacks integrated graphics.

Intel · Core i7
Core i7-840QM
4C / 8T3.2 GHz45 W
6.5
Full review
Top pick
Intel · Core i7 Extreme
Core i7-940XM
4C / 8T3.333 GHz55 W
7.5
Full review

The Bottom Line

Overview & Launch

Brand
Intel
Intel
Market
Mobile
Mobile
Segment
Mobile
Mobile High-End
Generation
1st Gen Core i7 (Clarksfield)
Core i7 Extreme (Clarksfield)
Launched
2010
2010
Status
End-of-life
End-of-life
Codename
Clarksfield
Clarksfield
Series
Core i7
Core i7 Extreme
Family
1st Generation
1st Gen Core i7
Predecessor
Core i7-820QM
Core i7-920XM
Successor
Sandy Bridge Quad
Core i7-2920XM

Specifications Compared

Cores & Clocks
Cores
4
4
Threads
8
8
Base Clock
1.867 GHz
2.133 GHz
Boost Clock
3.2 GHz
3.333 GHz
Cache & Power
L3 Cache
8 MB
8 MB
TDP
45 W
55 W
Architecture
Architecture
Clarksfield
Clarksfield
Process Node
45nm
45nm
Memory
Memory Type
DDR3
DDR3
Memory Speed
1333 MT/s
1333 MT/s
Memory Channels
Dual (2)
Dual (2)
Platform & I/O
Socket
Intel Socket G1
Intel Socket G1
PCIe Version
Gen 2
Gen 2
PCIe Lanes
16
16
Integrated GPU
None
None
Unlocked
No
Yes

Performance Compared

Productivity

Core i7-840QMBest45

8 threads and 8MB cache help with heavy multitasking.

Core i7-940XM36

Slightly faster than the 920XM but still heavily outclassed by modern CPUs.

Gaming

Core i7-840QM35

Good for 2010 games but low single-core by modern standards.

Core i7-940XMBest42

Handles legacy games well but bottlenecks modern GPUs and games.

Virtualization

Core i7-840QMBest60

Excellent for legacy VMs with VT-d support.

Core i7-940XM46

Adequate for legacy mobile VMs but lacks modern I/O.

Efficiency

Core i7-840QMBest25

45W TDP on 45nm is very hot and power-hungry.

Core i7-940XM20

Power hungry and inefficient by modern standards.

Specialized Performance

AI / ML

Core i7-840QMNone
  • No AI hardware
Core i7-940XMNone
  • No AI hardware support
  • Pure legacy x86 performance

Content Creation

Core i7-840QMGood
Legacy Premiere ProBlenderAutoCAD
Core i7-940XMLegacy
Legacy Video EditingLegacy 3D ModelingAudio Production

Gaming

Core i7-840QMFair
  • Requires discrete GPU
  • Can bottleneck modern games
  • Good for retro gaming
Core i7-940XMLegacy
  • Highest clocks for Socket G1
  • No integrated graphics
  • Bottlenecks modern GPUs

Industry Impact

Gaming
High
Moderate
Workstations
High
Moderate
Content Creation
High
Moderate
Virtualization
High
Moderate

Best CPU by Use Case

3D Rendering
Good
Good
Video Encoding
Good
Virtualization
Excellent
Gaming
Fair
Mobile Gaming
Excellent (for 2010)
Video Editing
Very Good
Basic Productivity
Overkill

Target Audience

Gamers
Targeted
Content Creators
Targeted
Developers
Targeted
Workstation Users
Targeted
Streamers
Office / Productivity
Students

Strengths & Weaknesses

Core i7-840QM

Pros

  • Large 8MB L3 cache
  • High 3.2 GHz turbo boost
  • 8 threads for multitasking
  • Socketed (Socket G1)

Cons

  • Very hot running (45W)
  • No integrated graphics
  • Obsolete 45nm process
  • Expensive at launch
Core i7-940XM

Pros

  • Fastest Socket G1 CPU
  • Unlocked multiplier
  • High turbo clock
  • 8MB L3 cache

Cons

  • Extremely power hungry
  • No integrated graphics
  • Obsolete platform
  • Produces excessive heat

Competitors & Alternatives

Core i7-840QM

  • AMD Phenom II X4 X940

    Mobile

    Rival
  • Intel Core i7-820QM

    Mobile

    Rival
  • Intel Core i7-740QM

    Mobile

    Rival
  • Intel Core 2 Extreme QX9300

    Mobile

    Rival
  • Intel Core i7-920XM

    Mobile Extreme

    Rival
  • Intel Core i7-2720QM
    Alt

    Newer Sandy Bridge alternative with vastly better efficiency.

Core i7-940XM

  • Intel Core i7-920XM

    Mobile Extreme

    Rival
  • Intel Core i7-840QM

    Mobile High-End

    Rival
  • AMD Phenom II X4 Mobile

    Mobile High-End

    Rival
  • Intel Core i7-740QM

    Mobile Mid-Range

    Rival
  • Intel Core 2 Extreme QX9300

    Legacy Mobile Extreme

    Rival
  • Intel Core i7-2820QM
    Alt

    Massive leap in efficiency and performance (Sandy Bridge).

  • AMD A8-3550MX
    Alt

    More efficient, though weaker, alternative.

  • Intel Core i5-2520M
    Alt

    Dual-core but vastly superior efficiency and single-thread speed.

Our Verdict on Each

Core i7-840QMSituational

A top-tier mobile CPU in 2010, offering excellent multi-threaded performance and a large cache, but runs hot and is obsolete today.

Best for: Repairing a legacy mobile workstation

Read the full review
Core i7-940XMSituational

The fastest Clarksfield chip, offering a minor clock speed bump over the 920XM, but equally obsolete today.

Best for: Upgrading an existing high-end 2010 DTR laptop.

Read the full review

Frequently Asked Questions

Which is better, Core i7-840QM or Core i7-940XM?

Based on our editorial ratings, the Core i7-940XM 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, Core i7-840QM or Core i7-940XM?

For gaming, the Core i7-940XM leads with a gaming performance score of 42/100 among Core i7-840QM and Core i7-940XM.

Which uses less power?

The Core i7-840QM has the lowest rated TDP. Power draw across these chips: Core i7-840QM (45 W), Core i7-940XM (55 W).

Do Core i7-840QM and Core i7-940XM use the same socket?

Yes — all of these CPUs use the Intel Socket G1 socket, so they share compatible motherboards.