CPU Comparison
Intel Core i5-2500K vs Intel Core i5-2405S
A side-by-side comparison of specs, performance and value. The Intel Core i5-2500K is an unlocked 95 W quad-core Sandy Bridge desktop processor that revolutionized enthusiast overclocking with its accessible multiplier adjustments, featuring 3.3 GHz base, 3.7 GHz turbo, and Intel HD 3000 graphics.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Fast for its era, but lacks the threads and IPC for modern productivity suites.
CPU performance is identical to the i5-2400S, adequate for legacy apps.
Gaming
When overclocked to 4.5 GHz+, it can still handle older esports titles, but is heavily bottlenecked in modern CPU-intensive games.
HD 3000 can handle very old games, but nothing modern.
Virtualization
Lacks VT-d, which limits advanced virtualization passthrough configurations, though basic VT-x works fine.
VM performance is constrained by the 4-thread limit.
Efficiency
When overclocked, power consumption can easily exceed 150 W, making it highly inefficient by modern standards.
Excellent power metrics for a quad-core chip of its era.
Specialized Performance
AI / ML
- No AI acceleration hardware
- Lacks AVX2 and modern vector instructions required for AI frameworks
- Completely unsuitable for AI workloads
- No AI acceleration capabilities
Content Creation
Gaming
- At stock speeds, it is outperformed by modern budget CPUs
- When overclocked to 4.5+ GHz, it remains playable in older esports titles like CS:GO
- Severe bottleneck in modern open-world and CPU-heavy games
- PCIe 2.0 may slightly limit top-tier GPU performance
- HD 3000 is noticeably faster than HD 2000 in legacy titles
- Still lacks DirectX 12 support
- Not viable for 3D gaming past 2012 standards
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- Legendary overclocking headroom (4.5-5.0 GHz on air/water)
- Unlocked multiplier made tuning accessible to beginners
- Intel HD 3000 with Quick Sync was excellent for video encoding
- Launched at an incredibly competitive $216
- Historic significance in the enthusiast PC community
Cons
- No Hyper-Threading (4 cores, 4 threads)
- Limited to PCIe 2.0
- Lacks VT-d for advanced virtualization
- High power draw when overclocked
- Completely obsolete for modern gaming and productivity
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
Competitors & Alternatives
Intel Core i5-2500K
- AMD Phenom II X4 980Rival
Desktop Performance
- AMD Bulldozer FX-4150Rival
Desktop Enthusiast
- Intel Core i7-2600KRival
Desktop Premium
- Compare head-to-headIntel Core i5-2400Rival
Desktop Mainstream
- AMD FX-6100Rival
Desktop Multi-thread
Ivy Bridge successor with PCIe 3.0, better integrated graphics, and cooler running temperatures.
Compare head-to-head- AMD Ryzen 5 5600Alt
A modern budget option that offers vastly superior performance for a similar inflation-adjusted price.
Intel Core i5-2405S
- AMD A8-3850Rival
Desktop APU
- AMD A6-3670Rival
Desktop APU
- Compare head-to-headIntel Core i5-2400SRival
Desktop
- Intel Core i3-2125Rival
Desktop
- AMD Phenom II X4 860TRival
Desktop
Better CPU clocks and better graphics within the same 65W TDP.
Compare head-to-head- AMD A10-5700Alt
Newer APU platform with significantly better graphics.
- Intel Core i7-2600SAlt
Adds Hyper-Threading for better multi-tasking.
- Intel Xeon E3-1245Alt
Similar HD 3000 graphics but in an 80W standard-power package.
Our Verdict on Each
A historic processor that offered unmatched overclocking headroom for its price. While obsolete for modern gaming, its legacy as the king of early 2010s budget performance is well-deserved.
Best for: Restoring a vintage 2011 gaming rig or for a collector wanting a piece of PC hardware history.
Read the full reviewA 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 reviewFrequently Asked Questions
Which is better, Intel Core i5-2500K or Intel Core i5-2405S?
Based on our editorial ratings, the Intel Core i5-2500K comes out ahead with a score of 7/10. 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 i5-2500K or Intel Core i5-2405S?
For gaming, the Intel Core i5-2500K leads with a gaming performance score of 22/100 among Intel Core i5-2500K and Intel Core i5-2405S.
Which uses less power?
The Intel Core i5-2405S has the lowest rated TDP. Power draw across these chips: Intel Core i5-2500K (95 W), Intel Core i5-2405S (65 W).
Do Intel Core i5-2500K and Intel Core i5-2405S 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 i5-2500K posts the highest multi-core benchmark score. Multi-core results: Intel Core i5-2500K (4,200), Intel Core i5-2405S (2,400). Benchmark figures are approximate and workload-dependent.