Hard-working disassembly sleuths at iFixIT spent their Easter weekend tearing an iPad apart to explore the Apple-designed A4 processor which powers the device.
iSuppli tore an A4 chip apart (above), revealing it to be an ARM processor featuring package-on-package construction to improve the speed and efficiency of internal processes.
Inside they found the RAM modules sit close by the processor, a move which speeds access to memory, cuts power consumption and reduces latency.
- The A4 has three layers: Two layers of RAM (Samsung K4X1G323PE), and one layer containing the actual microprocessor.
- This Package-on-Package construction gives Apple the flexibility to source the RAM from any manufacturer they want—they’re not locked into Samsung.
- Every iPhone processor has a Samsung part number on the processor die. “We have not found any Samsung markings on the A4 (outside of the DRAM), perhaps the clearest sign to date that Apple is in firm control of the semiconductor design.”
- Finally, they conclude Apple’s new A4 chip is a single core processor based on the ARM Cortex A8. (Apple had been expected to deliver a multicore chip based on the ARM Cortex A9.