The A5 chip almost twice the size of A4, fabbed on Samsung's 45nm process

Floorplan comparison: Apple’s A4 chip (left) and the latest A5 processor (right)

Reverse engineering wizards over at Chipworks put the A5 chip under a microscope. Yes, it’s a Samsung – confirming our hunch. The experts came to this conclusion by putting the chip under a microscope and examining dielectric layers and the shape of the transistor gates. The teardown analysis also revealed a die almost twice the size of the A4 chip from the previous-generation iPad and iPhone 4, the 45-nanometer manufacturing process and other interesting tidbits.

The new A5 chip (seen below) measures 10.1 x 12.1 millimeter versus 7.3 x 7.3 millimeter for the A4 chip from the original iPad. More space on the A5 silicon die is needed for an additional processing core and enhanced graphics, the chip experts explain:

Given that the A5 is a dual-ARM core, and has more graphics capability than the A4, more than doubling the size is to be expected, but it’s also a clue that this is still made in 45-nm technology.

Chipworks’ analysis echoes findings by UBM TechInsights that tore apart the iPad 2 and its A5 package. Their conclusion? Samsung produces the A5 chip on their 45-nanometer process, the same fabbing technology employed for the A4 chip. They also discovered DRAM modules from both Samsung and Elpida. And according to iSnoop, A5’s two processing cores feature workload-dependent, power-savvy variable clock speeds ranging from 861 MHz and 894. As we recently reported, Apple is rumored to be switching silicon manufacturing to Taiwan Semiconductor Manufacturing Co. (TSMC).

Some news pundits say this is a result of the increasing competition with Samsung. That doesn’t make sense, if you ask me. First, we know Apple pledged to prepay Samsung a whooping $7.8 billion in exchange for some components. Second, TSMC is a manufacturing partner for Nvidia, Qualcomm and Texas Instruments that provide a far greater variety and quantity of chips that power the vast majority of rival smartphones and tablets.

If you ask me, TSMC will be an alternative silicon supplier that will reduce Apple’s dependency on Samsung in the short run. In the long run, however, the deal will result in a smaller and more power-savvy A5 processor fabbed on TSMC’s 28 nanometer process.