Processor Speed on an iPadby John Lister
Apple has released five different iPads as of the time of publication: the original iPad in 2010; the iPad 2 in 2011; the new iPad, known unofficially as the iPad 3, in 2012; the iPad Mini in 2012 and the iPad with Retina display, known unofficially as the iPad 4, in 2012. Both the original iPad and the iPad 3 have been discontinued by Apple but can be bought secondhand from other suppliers. The processor, which is the component that physically carries out the calculations needed to perform computing tasks, varies across the range. Although the processor speed has only increased slightly during the iPad's history, other factors mean performance feels faster in later models.
All iPads use custom-designed Apple processors. The original iPad used the A4 chip, the iPad 2 and iPad Mini use the A5, the iPad 3 uses the A5X and the iPad 4 uses an A6X chip. In each case, the device uses a system on a chip, meaning both the main processor and separate graphics processor are housed on the same physical chip.
The speed of a computer device processor is measured in hertz, which is a physical measure of the speed electrical signals pass through it. This controls how many calculations the processor can carry out each second and how quickly the device runs. All iPads except the iPad 4 have a processor running at 1 GHz. The iPad 4 processor runs at 1.2 GHz.
Some processors have multi-core features; they act as if they were two or more separate processors. This allows them to carry out two separate calculations at once, making it much easier to run multiple applications simultaneously without freezes or delays. The original iPad had a single-core processor. The other iPads all have dual-core processors. Although the iPad 2, 3 and Mini processors don't run faster than the original iPad, the devices feel faster to the user.
Many computing devices, including the iPad range, use separate processors to handle graphics. As this is an intensive task, a separate graphics processor leaves the main processor able to better handle other computing tasks, again making performance feel faster. The original iPad used a single-core graphics processor, the iPad 2 and iPad Mini have a dual-core graphics processor, and the iPad 3 and 4 have quad-core graphics processors. This makes the later models better at handling complex graphics such as those found in games.