When Apple announced the Apple M4 chip during its iPad Pro event yesterday, it mentioned that the chip came with "up to" four high-performance CPU cores.
Those short, easily missable words always mean that there's a lower-end version of the chip coming that doesn't include that many CPU cores, and the tech specs page for the new iPad Pro has the full details: iPad Pros with 256GB or 512GB of storage use a version of the M4 with three high-performance CPU cores and six smaller efficiency cores. Only the models with 1TB and 2TB of storage have an M4 with all four high-performance CPU cores enabled.
The 256GB and 512GB models also ship with 8GB of RAM, where the 1TB and 2TB models come with 16GB of memory installed. Though these changes are clearly spelled out on the Tech Specs page, the actual configuration page for the iPad Pros in Apple's online store doesn't give any indication that upgrading storage also upgrades your CPU and RAM.
All M4 iPad Pros ship with a fully enabled 10-core GPU, 16-core Neural Engine, and 120 GB/s of memory bandwidth. And all M2 iPad Air models ship with the same fully enabled M2 chip and 8GB of RAM.
This is different from how Apple handles upgrades for Macs, which still generally allow flexible build-to-order configurations where you can upgrade individual specs without having to upgrade everything all at once.
This phenomenon isn't new, at least not for RAM. The 2018 iPad Pro with the Apple A12X—the first to shift to the modern slim-bezel design—included 4GB of RAM in the base models and 6GB of RAM in the 1TB model. The M1 and M2 iPad Pros each shipped with 8GB of RAM in their lower-end configurations and 16GB in the 1TB and 2TB configurations. This is, however, the first time that Apple has tied the iPad's CPU performance to storage capacity, and it means that the base-model iPad Pros won't deliver as large an upgrade over the M2 models as the more-expensive versions.
As for why Apple does this for its CPUs, it's not just a way to upsell potential buyers to higher-end iPads. Silicon chips often come out with small flaws, especially when they're made using brand-new manufacturing processes like the second-generation 3 nm process used for the M4. Selling a partially disabled version of the chip allows Apple (and other chipmakers) to use imperfect silicon dies instead of throwing them out, a process known as "binning."
The 1TB and 2TB iPad Pros are also the only ones that can be upgraded with Apple's "nano-texture glass," which gives your screen a flat matte finish rather than a glossy, glassy one. The nano-texture upgrade costs $100 on top of the $600 you'll spend to upgrade the storage and other components.
