CPU Comparison
Intel Core i5-655K vs Intel Core i5-661
A side-by-side comparison of specs, performance and value. The Intel Core i5-655K is an unlocked dual-core Clarkdale processor launched in May 2010, offering BCLK multiplier freedom for enthusiast overclockers on the LGA 1156 platform.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Two cores are fundamentally insufficient for any modern productivity workload.
Identical CPU performance to the i5-660, inadequate for modern productivity.
Gaming
Even overclocked, the dual-core architecture and weak iGPU make modern gaming impossible.
The 900MHz iGPU was slightly more capable than other Clarkdales but still cannot handle any modern 3D workload.
Virtualization
Minimal utility with only two cores and 4GB-friendly memory limits.
Two cores with Hyper-Threading offer minimal virtualization capability.
Efficiency
73W base TDP increases significantly when overclocked, resulting in poor efficiency.
87W TDP for a dual-core with basic integrated graphics represents very poor efficiency.
Specialized Performance
AI / ML
- No AI acceleration capabilities
- Completely unsuitable for any machine learning task
- No AI capabilities
- Completely unsuitable for machine learning
Content Creation
Gaming
- Overclocking does not overcome the dual-core limitation
- HD Graphics at 733MHz cannot handle any modern 3D workload
- Was marginal for 2010 gaming even with a discrete GPU
- 900MHz iGPU was the fastest in Clarkdale but still far too slow for modern games
- Could handle very light 2010-era games at low resolution
- A discrete GPU was still necessary for any serious gaming
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- Unlocked multiplier was rare and valuable for LGA 1156 overclocking
- 32nm process allowed impressive frequency headroom
- Interesting piece of Intel's overclocking history
- BCLK-independent overclocking simplified tuning
Cons
- Only two cores even when overclocked
- More expensive than the identical-performance i5-650 at launch
- Clarkdale's dual-die design limited memory controller performance
- No practical use in modern computing
- Overclocking a dual-core provides negligible real-world benefit today
Pros
- Fastest integrated graphics in the Clarkdale lineup
- Same capable dual-core CPU as the i5-660
- Good hardware video decode acceleration
- Interesting variant for collectors
Cons
- 87W TDP is high for a dual-core with basic iGPU
- GPU improvement was marginal in practice
- Same two-core limitation as all Clarkdale i5s
- No AVX instruction support
- Completely obsolete platform
Competitors & Alternatives
Intel Core i5-655K
- AMD Phenom II X2 560 Black EditionRival
Unlocked Dual-Core
- AMD Phenom II X4 955 Black EditionRival
Unlocked Quad-Core
- Compare head-to-headIntel Core i5-750Rival
Mainstream Quad-Core
- Intel Core i7-860Rival
Lynnfield i7
- AMD Athlon II X4 645Rival
Budget Quad-Core
- AMD Phenom II X4 955 BEAlt
Unlocked quad-core at a competitive price with better multi-threaded throughput.
- Intel Core i7-870Alt
Eight threads on the same platform if budget allowed.
Intel Core i5-661
- AMD Athlon II X4 640Rival
Budget Quad-Core
- AMD Phenom II X2 565Rival
Dual-Core Desktop
- Compare head-to-headIntel Core i5-750Rival
Quad-Core Desktop
- AMD 880G Integrated PlatformRival
Integrated Graphics Platform
- NVIDIA GeForce 9400 GT + Pentium E6600Rival
Budget Discrete GPU Combo
Same CPU performance with 14W lower TDP for $10 less.
Compare head-to-head- AMD 880G PlatformAlt
Better integrated graphics performance from AMD's platform at lower cost.
Our Verdict on Each
An interesting novelty for overclockers in 2010, but the unlocked multiplier on a dual-core Clarkdale offered little practical value even at launch.
Best for: Collectors or overclocking hobbyists interested in legacy hardware
Read the full reviewThe faster 900MHz iGPU was a notable differentiator in 2010 but did not overcome the fundamental dual-core limitation. The 87W TDP was a significant penalty.
Best for: Running an existing i5-661 system for basic tasks
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i5-655K or Intel Core i5-661?
Based on our editorial ratings, the Intel Core i5-661 comes out ahead with a score of 3.5/10. 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 i5-655K or Intel Core i5-661?
For gaming, the Intel Core i5-661 leads with a gaming performance score of 7/100 among Intel Core i5-655K and Intel Core i5-661.
Which uses less power?
The Intel Core i5-655K has the lowest rated TDP. Power draw across these chips: Intel Core i5-655K (73 W), Intel Core i5-661 (87 W).
Do Intel Core i5-655K and Intel Core i5-661 use the same socket?
Yes — all of these CPUs use the LGA 1156 socket, so they share compatible motherboards.
Which is faster in multi-core benchmarks?
The Intel Core i5-661 posts the highest multi-core benchmark score. Multi-core results: Intel Core i5-655K (4,380), Intel Core i5-661 (4,600). Benchmark figures are approximate and workload-dependent.