CPU Comparison

Intel Core i5-2405S vs Intel Core i5-2550K

A side-by-side comparison of specs, performance and value. The Intel Core i5-2405S is a specialized 65W quad-core processor that distinguishes itself from the i5-2400S through its integrated graphics. While sharing the same 2.5 GHz base clock and 3.3 GHz turbo boost, Intel equipped this chip with the Intel HD 3000 graphics processor instead of the HD 2000. The HD 3000 features 12 Execution Units, doubling the graphics rendering capabilities. This made the i5-2405S an ideal choice for small form factor business PCs that required slightly better graphical throughput for entry-level 3D applications or dual-display setups without adding a dedicated GPU.

Intel · Core i5
Intel Core i5-2405S
4C / 4T3.3 GHz65 W
4.5
Full review
Top pick
Intel · Core i5
Intel Core i5-2550K
4C / 4T3.8 GHz95 W
5.5
Full review

The Bottom Line

Overview & Launch

Brand
Intel
Intel
Market
Desktop
Desktop
Segment
Desktop
Desktop
Generation
2nd Gen
2nd Gen Core i5 (Sandy Bridge)
Launched
2011
2012
Status
Discontinued
End-of-life
Codename
Sandy Bridge
Sandy Bridge
Series
Core i5
Core i5
Family
Sandy Bridge
Sandy Bridge
Predecessor
Intel Core i5-660S
Intel Core i5-2500K
Successor
Intel Core i5-3475S
Intel Core i5-3570K

Specifications Compared

Cores & Clocks
Cores
4
4
Threads
4
4
Base Clock
2.5 GHz
3.4 GHz
Boost Clock
3.3 GHz
3.8 GHz
Cache & Power
L3 Cache
6 MB
6 MB
TDP
65 W
95 W
Architecture
Architecture
Sandy Bridge
Sandy Bridge
Process Node
32nm
32nm
Memory
Memory Type
DDR3
DDR3
Memory Speed
DDR3-1333
DDR3-1600
Memory Channels
Dual (2)
Dual (2)
Max Memory
32 GB
32 GB
Platform & I/O
Socket
LGA 1155
LGA 1155
PCIe Version
PCIe 2.0
PCIe 2.0
PCIe Lanes
16
16
Integrated GPU
Yes
None
Unlocked
No
Yes

Performance Compared

Productivity

Intel Core i5-2405S25

CPU performance is identical to the i5-2400S, adequate for legacy apps.

Intel Core i5-2550KBest36

Marginally faster than the 2500K in multi-threaded tasks due to 100 MHz higher clocks, but still inadequate for modern software.

Gaming

Intel Core i5-2405S18

HD 3000 can handle very old games, but nothing modern.

Intel Core i5-2550KBest23

The slight clock bump over the 2500K is imperceptible in games. Still completely obsolete for modern titles.

Virtualization

Intel Core i5-2405SBest35

VM performance is constrained by the 4-thread limit.

Intel Core i5-2550K30

Lacks VT-d, and the lack of an iGPU means no iGPU passthrough, reducing its utility in virtualization setups.

Efficiency

Intel Core i5-2405SBest75

Excellent power metrics for a quad-core chip of its era.

Intel Core i5-2550K35

Despite the disabled iGPU, power consumption when overclocked is still very high by modern standards.

Specialized Performance

AI / ML

Intel Core i5-2405SNone
  • No AI acceleration capabilities
Intel Core i5-2550KNone
  • No AI hardware
  • Lacks AVX2 and modern instruction extensions
  • Unable to handle any practical AI workload

Content Creation

Intel Core i5-2405SUnsupported
Intel Core i5-2550KPoor
Basic Code Compilation

Gaming

Intel Core i5-2405SPoor
  • HD 3000 is noticeably faster than HD 2000 in legacy titles
  • Still lacks DirectX 12 support
  • Not viable for 3D gaming past 2012 standards
Intel Core i5-2550KPoor
  • Virtually identical gaming performance to an overclocked i5-2500K
  • Cannot function without a discrete graphics card
  • Modern games are heavily CPU-limited on this architecture

Industry Impact

Gaming
Negligible
Low
Workstations
Negligible
Negligible
Content Creation
Low
Negligible
Virtualization
Low
Negligible

Best CPU by Use Case

Dual-Monitor Office Work
Good
Video Transcoding
Fair
Light Photoshop
Poor
Media Playback
Good
Overclocking with Discrete GPU
Excellent
CPU Collection
Good
Retro Gaming
Good
Dedicated Gaming Rig
Poor
Media Encoding without Quick Sync
Poor

Target Audience

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

Strengths & Weaknesses

Intel Core i5-2405S

Pros

  • Intel HD 3000 integrated graphics
  • Quick Sync Video support
  • Low 65W power draw
  • Full 6 MB L3 cache

Cons

  • Rare and potentially expensive on the used market
  • No Hyper-Threading
  • Lower clocks than standard 95W parts
  • Lacks AVX2
  • Not Windows 11 compatible
Intel Core i5-2550K

Pros

  • Slightly higher clocks out of the box than the 2500K
  • Unlocked multiplier for easy overclocking
  • Disabled iGPU meant 100% of the die was dedicated to CPU tasks
  • Has become a unique collector's piece
  • No iGPU driver conflicts for pure discrete GPU systems

Cons

  • No integrated graphics whatsoever
  • Lost Intel Quick Sync video encoding
  • More expensive at launch than the 2500K for negligible gains
  • Lacks VT-d
  • No Hyper-Threading

Competitors & Alternatives

Intel Core i5-2405S

  • AMD A8-3850

    Desktop APU

    Rival
  • AMD A6-3670

    Desktop APU

    Rival
  • Compare head-to-head
  • Intel Core i3-2125

    Desktop

    Rival
  • AMD Phenom II X4 860T

    Desktop

    Rival
  • Better CPU clocks and better graphics within the same 65W TDP.

    Compare head-to-head
  • AMD A10-5700
    Alt

    Newer APU platform with significantly better graphics.

  • Intel Core i7-2600S
    Alt

    Adds Hyper-Threading for better multi-tasking.

  • Intel Xeon E3-1245
    Alt

    Similar HD 3000 graphics but in an 80W standard-power package.

Intel Core i5-2550K

Our Verdict on Each

A niche OEM processor that offered better integrated graphics in a low-power package, now mostly useful for exact-match legacy repairs.

Best for: Replacing a failed CPU in a 2011 Apple iMac or premium AIO

Read the full review

An intriguing engineering footnote that disabled the iGPU for theoretical overclocking gains, but its minor clock bump and higher price over the 2500K made it one of the least relevant 'K' series processors Intel ever launched.

Best for: Purchasing as a collector's item to complete a Sandy Bridge CPU collection.

Read the full review

Frequently Asked Questions

Which is better, Intel Core i5-2405S or Intel Core i5-2550K?

Based on our editorial ratings, the Intel Core i5-2550K comes out ahead with a score of 5.5/10. 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 i5-2405S or Intel Core i5-2550K?

For gaming, the Intel Core i5-2550K leads with a gaming performance score of 23/100 among Intel Core i5-2405S and Intel Core i5-2550K.

Which uses less power?

The Intel Core i5-2405S has the lowest rated TDP. Power draw across these chips: Intel Core i5-2405S (65 W), Intel Core i5-2550K (95 W).

Do Intel Core i5-2405S and Intel Core i5-2550K use the same socket?

Yes — all of these CPUs use the LGA 1155 socket, so they share compatible motherboards.

Which is faster in multi-core benchmarks?

The Intel Core i5-2550K posts the highest multi-core benchmark score. Multi-core results: Intel Core i5-2405S (2,400), Intel Core i5-2550K (4,500). Benchmark figures are approximate and workload-dependent.