If you’re thinking about buying a used iPad, the iPad 3 and iPad 4 may offer the biggest savings. The iPad 3 was the first iPad to feature a Retina display, but other than a larger graphics chip to drive the higher-resolution screen, it was mostly an iPad 2. The iPad 4 also has a Retina display, but this one has a faster processor and a more modern connector.
iPad 4 vs. iPad 3 speed test | Pocketnow
The iPad 4 was the first iPad to be released in the fall instead of the spring. With its new processor, it was the first major upgrade to the iPad since the iPad 2.
If Apple had used the same naming system for the iPad as it did for the iPhone, the iPad 4 would have been called the iPad 3S, with the S standing for speed. The biggest difference between the iPad 3 and the iPad 4 is a processor that is twice as fast, both in graphics and processing power.
Many expected the A6X to debut with the iPad 3, but Apple didn’t want to sacrifice battery life in an iPad that already needed as much power as possible to deliver on the Retina display. The A6X was delayed to ensure it was ready for mass consumption, including energy efficiency.
