When Apple unveiled their new iPad early last month, they also announced that last year’s model, the iPad 2, would be getting a reduction in price. Each model of iPad 2 got a $100 price reduction in the wake of the new iPad announcement, dropping the price for the lowest-end model, the 16GB Wi-fi only version – down to $399.

This is pretty standard practice for Apple: a new product comes out at the same price points as the previous model, and the previous model gets a price cut. That’s why you could get an iPhone 3GS for free with a two-year contract after the iPhone 4S launched last year. What Apple doesn’t do, however, is upgrade the old versions. Except this time, that’s exactly what they did.

It seems that the iPad 2 models that are currently rolling off the production line have a slightly more energy-efficient processor the A5 chip that has been in the tablet since it launched last year. This modified version of the A5 is the same chip that’s found in the new third-gen Apple TV that launched alongside the new iPad.

According to AnandTech’s Brian King, who first made the discovery, the updated A5 chip is the same design as the old one, but “ported” to Samsung’s new 32nm HKMG manufacturing process. The result is a chip that performs almost identically to the old version, but does it with somewhat improved energy efficiency. For the end user, then, the upgrade doesn’t necessarily mean much, except that those who get the latest version of the iPad 2 may see slightly better battery performance than those who have the older version.

Meanwhile, Chipworks confirmed the presence of the new chip inside the iPad 2 in the simplest way possible: they took one apart and looked. Here’s what the chip looks like:

While they suspect that a similar change has been made in more recently-produced models of the iPhone 4S, they have not yet managed to confirm that.