Consumers interested in more storage on their fourth-generation iPad can get their app- and file-hoarding fix beginning Tuesday. The newest variant of the Retina Display iPad is now available in Apple Stores and at Apple.com. The device, which is in all other respects identical to the model already for sale, doubles the maximum storage capacity from 64 GB to 128 GB.

The 128-GB iPad starts at $799 for the Wi-Fi-only model. Adding a cellular radio, including LTE 4G and 3G for various wireless networks in the U.S. and beyond, bumps the price up by another $130 to a staggering $929. It is compatible with the LTE 4G networks operating by AT&T, Sprint and Verizon Wireless. Data access plans for the iPad cost extra.

In addition to the incredible storage capacity, the 128-GB iPad has a 9.7-inch display, an A6x processor, dual cameras, 10 hours of battery life and a Lightning port.

Apple envisions the 128-GB iPad to be a good fit for working people. "With twice the storage capacity and an unparalleled selection of over 300,000 native iPad apps, enterprises, educators and artists have even more reasons to use iPad for all their business and personal needs," said Philip Schiller, Apple's senior VP of worldwide marketing. With a Bluetooth keyboard, the 128-GB iPad rivals some laptops in productivity potential.

[ Of those 300,000 iPad apps, which are must-haves? See the 12 Best iPhone, iPad Apps Of 2012. ]

According to Apple.com's iPad page, the Wi-Fi model is shipping in one to three days in most regions. The 4G model is shipping in three to five days. Shipping times may fluctuate depending on Apple's supply chain and the particular model being selected (AT&T versus Sprint or Verizon).

Speaking of Apple's supply chain, the iPad Mini is generally becoming more widely available as supply catches up with demand.

For the last month or so, the device wasn't shipping from Apple.com in fewer than five to seven days. It has recently improved to shipping in one to three days. The iPad Mini can be picked up at Apple's retail stores, as well.

This change could reflect a seasonal slowdown in device sales after the holidays, a shift in Apple's manufacturing output or a combination of the two.

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