updated 09:00 pm EDT, Mon April 5, 2010
Chip explored using scanning electron microscope
Following iFixit's recent iPad teardown, the company has proceeded to delve one step further by dissecting Apple's A4 chip. Chipworks, a semiconductor reverse-engineering company, helped destroy the device and explore its components using professional lab equipment such as scanning electron microscopes (SEMs) and high resolution x-ray machines.
The A4 chip is configured as a package-on-package (PoP) component with three primary layers. A cross-section image shows the ARM processor below both 1Gb RAM dies. While the iPhone processors have shown Samsung labeling on the processor dies, the iPad component reportedly shows Samsung tags only on the RAM dies.
iFixit suggests the A4 is very similar to the Samsung processor used in the iPhone. Corroborating earlier reports, the company also believes the processor is a single-core Cortex A8 design rather than the unconfirmed multi-core A9 component.
Although Chipworks and iFixit continued to investigate other chips on the iPad's logic board, the companies could use the hardware observations to confirm the GPU design.
Recent reports suggest the A4 chip is faster than the 1GHz Qualcomm components used in Google's Nexus One. Apple's design averaged 10-percent faster performance when loading websites, although the tests were not an absolute comparison as both devices utilize different browsers.