In the lead up to the launch of the new iPhone, Apple has reportedly placed its largest order yet for next-generation models: 70-80 million units by December 30th of this year. In contrast, Apple ordered 50-60 million units for the launch of the iPhone 5s and 5c.

There are several reasons as to why Apple has made such a large order of new iPhones. One is that they're expecting record demand for the upcoming phones, which are expected to be available as 4.7- and 5.5-inch models. The larger displays will close the hardware gap between the iPhone and other flagship smartphones, meaning demand will likely increase compared to previous launches.

The increase in orders could also be attributedĀ to Apple's recent partnership with China Mobile, the largest wireless carrier in the world. The launch of the upcoming iPhone could be the first where Chinese buyers can order the smartphone at the same time as other nations, increasing global demand.

Either way, the launch of the next-generation iPhone is going to be a big one. Aside from larger displays, the new iPhones are widely expected to include tougher synthetic-sapphire glass, a better camera, and the usual selection of performance improvements.