Intel introduced the Core 2 Quad processors in 2007 and followed up with three generations of the Quad-Core i3, i5 and i7 processors. Intel launched the latest generation in April 2012. It has an improved architecture and is designed for high-performance and low power consumption in laptops and desktop computers. An integrated graphics processing unit and the inclusion of large amounts of cache memory on the chip bring these CPUs closer to the computer-on-a-chip model that can reduce costs without sacrificing functionality or speed.
The processors use the new 22-nanometer technology, which shrinks structures on the chip by about 30 percent from previous generations. The smaller structures allow faster processing times and reduce power consumption. The new technology also introduces three-dimensional transistors in which the gate electrode surrounds the source and drain and results in higher currents at low voltages. This last development is especially beneficial for mobile processors. The changes allow Intel to place more transistors on smaller chips, reducing cost without sacrificing performance.
For Quad-Core processors, each processor runs at a given speed, but the equivalent speed to a single-core processor depends on how well the computer and software handle four processors simultaneously. Such multithreading gives a higher equivalent speed for the four-core arrangement, although it is not four times the speed of one core. For the latest Intel Quad-Core processor generation, the i3 processor has a speed ranging from 1.6 to 3.4 GHz. The i5 and i7 processor speeds are 2.8 to 3.8 GHz and 2.8 to 3.9 GHz respectively (see Resources). The exact speed depends on the model of the processor. These speeds are as high as those achieved by single-core processors, so the four-core arrangement should result in much faster performance in most applications.
Despite high performance, Intel has reduced the power consumption, allowing for longer battery life in mobile devices and less cooling for desktop computers. The i3 processor power consumption ranges from 17 W to 55 W while the i5 and i7 range from 17 W to 77 W (see Resources). In general, the higher speeds have a higher power consumption, although some models don’t follow the general trend because they are optimized for low power.Graphics Processor
The new processors have a powerful graphics processing unit on the chip. It supports 3D HD video and graphics and is fact enough for mainstream gaming. The improvements in technology let this unit perform at double the level of the previous processor generation’s GPU. For consumer laptops and desktops this means that they need no separate graphics card.
A large amount of cache memory is built into each processor. L1 cache is for data and instructions for each processor core and is 64 KB. The L2 cache takes over when L1 is full and is 256 KB per core. For the general purpose L3 cache, the i3 has 3 MB while the i5 has 3 to 6 MB and the i7 has 4 to 8 MB of memory. The L3 cache is shared between all four cores and the GPU. The relatively large cache means the processor can quickly access data on the chip rather than having to rely on the larger but more remote system random access memory.