Intel Core i5-661

The Intel Core i5-661 is a dual-core Clarkdale processor distinguished by its faster 900MHz integrated graphics, trading higher power consumption for improved iGPU performance.

The Core i5-661 shared the same 3.33GHz dual-core CPU as the i5-660 but featured Intel HD Graphics running at 900MHz instead of 733MHz. This 23% increase in GPU clock came at a cost: the TDP rose from 73W to 87W, a 19% increase in power consumption for what amounted to a small improvement in light gaming and media playback capability.

The Core i5-661 launched on January 7, 2010, as the most unusual SKU in Intel's Clarkdale lineup. While every other Clarkdale i5 settled on a 73W TDP with 733MHz integrated graphics, the i5-661 pushed the graphics die to 900MHz, bumping the TDP to 87W. It was an experiment in whether a faster iGPU could make dual-core integrated graphics more palatable to users who might otherwise buy a discrete card.

</br></br>Reviews were universally lukewarm. The 23% GPU clock increase translated to perhaps 10-15% improvement in light gaming scenarios, which was rarely enough to make a game playable that wasn't already playable at 733MHz. Meanwhile, the 87W TDP meant the i5-661 drew more power than the quad-core i5-750 at 95W while offering dramatically less CPU performance.

Reviewers at AnandTech and Tom's Hardware both questioned the product's reason for existence.</br></br>The i5-661 quietly faded from the market. OEMs largely preferred the 73W i5-660 for its lower power consumption, and enthusiasts who wanted graphics performance simply added a discrete GPU to a Lynnfield system.

In retrospect, the i5-661 was a failed experiment that demonstrated Intel's early struggles with balancing integrated graphics performance against power consumption, a challenge they would not truly solve until Sandy Bridge's HD 2000/3000 graphics a year later.