The A9X features an Apple-designed 64-bit ARMv8-A dual-core CPU called "Twister". Unlike the
A9, the A9X does not contain an
L3 cache due to its significant
DRAM bandwidth. The A9X is paired with 4 GB of
LPDDR4 memory in the 12.9" iPad Pro and 2 GB of LPDDR4 memory in the 9.7" iPad Pro with a total bandwidth of 51.2 GB/s. This high bandwidth is necessary to feed the SoC's custom 12-core
PowerVR Series7XT GPU. The RAM is not included in the A9X package unlike its sibling, the
A9. The A9X uses the same NAND interface as the A9, which uses an Apple-designed
NVMe-based controller that communicates over a
PCIe connection. The iPad Pro's NAND design is more akin to a PC-class
SSD than embedded flash memory common on mobile devices. This gives the iPad Pro a significant storage performance advantage over competitors which often use
mSATA or
eMMC to connect to their storage systems. The A9X has video codec encoding support for
H.264. It has decoding support for
HEVC, H.264,
MPEG‑4, and
Motion JPEG. == Products that include the Apple A9X ==