iPhone 4

Introduction The iPhone 4 is a slate smartphone developed by

Apple. It is the fourth generation of iPhone, and successor to the iPhone 3GS. It is particularly marketed for video calling, consumption of media such as books and periodicals, movies, music, and games, and for general web and e-mail access. It was announced on June 7, 2010, at the WWDC 2010 held at the Moscone Centre, San Francisco,

and was released on June 24, 2010 in the United States, the United Kingdom, France, Germany and Japan.

Display The display of the iPhone 4 is designed by Apple

and is manufactured by LG. It features an LED backlit TFT LCD capacitive touchscreen with a pixel density of 326 pixels per inch (ppi) on a 3.5 in (8.9 cm) (diagonally measured), 960×640 display. Each pixel is 78 micrometres in width. The display has a contrast ratio of 800:1. The screen is marketed by Apple as the "Retina Display", based on the assertion that a display of approximately 300 ppi at a distance of 12 inches (305 mm) from one's eye is the maximum amount of detail that the human retina can process.

Processor And Memory The iPhone 4 is powered by the Apple A4 chip, which

was designed by Intrinsity and, like all previous iPhone models, manufactured by Samsung. This system-on-a-chip is composed of a Cortex-A8 CPU integrated with a PowerVR SGX 535 GPU. The Apple A4 is also used in the iPad where it is clocked at its rated speed of 1 GHz. The clock speed in the iPhone 4 has not been disclosed . All previous models of the iPhone have underclocked the CPU, which typically extends battery life and lowers heat dissipation.

The iPhone 4 has 512 MB of eDRAM. The additional eDRAM supports increased performance and multi-tasking.

Reviews

Reviews of the iPhone 4 have been generally favourable. Walt Mossberg of The Wall Street Journal called the device "the best device in its class". Engadget named it the "best smartphone on the market right now". CNET gave the iPhone 4 a rating of 8.6 out of 10, one of the highest ratings it has given any smartphone.TechRadar gave the device 4.5/5 stars. Consumer Reports said the signal problem was the reason they didn't rate it a "recommended" model, although the other tests ranked it highest among smart phones.

Joshua Topolsky of Engadget described the device's industrial design as being "more detailed and sophisticated" than its predecessor.