Intel Core i3-2100 Processor
 

The move from single to dual-core processors in the mainstream market happened rather quickly and firmly: both Intel and AMD just stopped developing single-core CPUs. The production continued, but such models were already made by cutting down dual-core ones. Intel also used the dual-core design in making of quad and hexacore processors, too. AMD, in turn, developed the initially quad-core Phenom, but continued to produce dual-core Athlons. The change in process technology and architecture resulted in as many as three independent lineups: Deneb, Propus and Regor. The latter was a special sort of dual-core design (also used in single-core Semprons). Intel, having mastered monolithic design, didn't stop making initially dual-core chips which still occupy the largest share of the market, especially in mobile PCs where the number of cores is rarely higher than two.

http://ixbtlabs.com/articles3/cpu/in...3-2100-p1.html