The Intel i3, the Intel i5 and the Intel i7 are the three divisions that make up semiconductor company Intel Corp.'s Core brand: a collection of consumer-oriented processors, or central processing units, for desktop and laptop PCs. They represent the Core's entry-level, mid-range and top-of-the-line processors, respectively. Although the Core brand is primarily a dual-core CPU, the Core i5 and the Core i7 offer quad-core entries as well.
At the time of publication, the Core i series is in its second generation of production. The first-generation chips — the Core i3, Core i5 and Core i7, debuted in 2010, 2009 and 2008, respectively — use the 45-nanometer manufacturing process. The second-generation CPUs, appearing in 2011, use the 32-nm manufacturing process instead, making them smaller chips. The Core i3 is strictly a dual-core processor, which means that it has two processing units. Intel adds a quad-core choice for the i5 and i7, which is twice as powerful as the dual-core variants. The i7, however, also has six-core chips.
Each Intel Core processor has a clock speed — or processing speed — which is the rate at which the chip executes its basic functions. The i3 has a clock, or processing, speed range of 1.2GHz to 3.33GHz. The Core i5 and the Core i7 clock speed ranges are 1.06GHz to 3.6GHz and 1.06GHz to 3.4GHz, respectively. The quad-core chips in particular have a clock speed range of 1.6GHz to 3.33GHz, placing them at the higher end of processing proficiency within the Core family.
Data Transfer Speed
Each Intel Core processor has a data transfer speed, which is the rate at which the CPU conducts data transfer with the computer's motherboard. The Core i5 and the Core i7 offer two data transfer speeds: 2.5 gigatransfers per second and 5GT/s, or 2.5 billion and 5 billion transfers per second. Intel adds 4.8GT/s and 6.4GT/s to the Core i7. The quad-core chips are available with any of the four aforementioned data transfer rates.
Each Intel Core CPU, regardless of classification or number of cores, has three caches. These are small memory units that the chip uses for high-speed access to the computer's most frequently used data. The third cache — the component that the processor relies on after failing to retrieve data from the first two — contains 3MB or 4MB on the i3, up to 8MB on the i5 and up to 12MB on the i7. Peak power consumption is up to 73 watts for the i3, up to 95W for the i5 and up to 130W for the i7.