What Is the Difference Between Intel I3, I5 & I7 Processors?

By Andy Josiah

The Intel i3, i5 and i7 first- and second-generation processors represent the low-end, mid-range and top-tier divisions of Core, which is semiconductor company Intel Corp's premier brand of consumer-oriented central processing units as of mid-2011. Consequently, the three computer chips contain several notable differences. Additionally, the Intel Core i7 has a performance-oriented subcategory dubbed Extreme Edition.

Main Description

The Intel Core i3, i5 and i7 processor brands are split into desktop and laptop (or mobile) processors. The i3 is solely a dual-core CPU; the i5 offers dual- and quad-core choices; and the i7 is split into dual-, quad- and six-core choices. The Intel i3/i5/i7 chips released from 2008 to 2010 use the 45-nanometer manufacturing process, while most post-2010 chips use the smaller 32-nm manufacturing process instead.

Speeds

With the desktop CPUs being generally faster than the mobile ones, the core (or processing) speed ranges of the Intel Core i3, i5 and i7 are 1.2 GHz to 3.33 GHz, 1.06 GHz to 3.6 GHz and 1.06 GHz to 3.46 GHz, respectively. Regarding data transfer speed, most Core chips use Intel's Direct Media Interface to achieve rates of 2.5 or 5 gigatransfers per second. A few i7 processors, however, use the company's QuickPath Interconnect link instead, thus yielding data transfer speeds as high as 6.4GT/s.

Smart Cache and Power

Each Intel Core i3, i5 and i7 processor has an Intel Smart Cache, which is a tiny storage unit that it uses for high-speed access to the computer's data. The Core i3's Smart Cache has 3MB or 4MB. Each Core i5 mobile chip has a 3-MB cache, while the desktop variant has 3MB, 4MB, 6MB and 8MB choices. The Core i7 tops them all with 4MB, 6MB, 8MB and 12MB, with the Extreme Edition chips sticking with the last two choices. Regarding power consumption, the Core mobile chips are more energy efficient than the desktop ones. However, the i7 has the highest maximum power consumption rating at 130 watts, compared with the i5's 95W and i3's 73W.

Technologies

The Intel Core i3 is the only division in the current Core line-up that lacks Intel's Turbo Boost Technology. This enables the processor to work at faster speeds when the computer system demands it for greater tasks. However, the i3 is the only Core category that has every single chip bearing the Intel HD Graphics brand, which enables graphics processing on the processor itself. This is because Intel began the practice in 2010, the year the i3 debuted. Since the i5 debuted in 2009, three of its earliest chips do not have the feature. The i7, with a debut date of 2008, has the Intel HD Graphics chipset missing on many of its CPUs.