Apple released the iPad Pro (2020) in March, with the new A12Z Bionic chipset inside. The A14 Bionic chipset is primary processing unit for the iPhone 12 and the iPad Air (2020). At the moment, the new iPad Pro is the only Apple’s device with the A12Z chipset. If you are a performance-junkie and want to upgrade to a new iPad model, it’s important to compare between A12Z and A14 chipsets.
When Apple developed the new iPad Pro (2020), the newer generation A13 Bionic was already available. So, it’s quite interesting why Apple chose a variant of A12 Bionic instead. The A12Z is an incremental upgrade of the A12X chip, used by iPad Pro (2018), another variant of the original A12 Bionic. The basic A12 chipset design for iPhone X, XS and XR includes hexa-core CPU and quad-core GPU. The A12X is a more powerful variant with octa-core CPU and hepta-core (7 cores) GPU. The 12Z is a slight upgrade of the 12X, with octa-core CPU and octa-core GPU.
Hardware Specs

CPU
The main module of the A14 Bionic chipset is the hexa-core CPU running at normal clock of 1.8GHz and boost clock of 3.01 GHz. As mentioned above, the A12Z comes with integrated octa-core CPU, but it runs slower at 1.59GHz normal clock and 2.49GHz boost clock. This means, A14 should be faster for single-core operations.

GPU
A-series Bionic chipsets have excellent graphical processing unit that can run demanding games at highest detail settings and good frame rates. The A14 has only quad-core GPU, but latest benchmarks show that it’s among the most powerful GPU in the mobile industry today. The A12Z offers an octa-core GPU module, which could be beneficial in many multi-core graphics processing tasks.
RAM
If you prefer the iPad Air (2020), it only has 4GB of RAM, which could limit multitasking performance somewhat. The new iPad Pro (2020) comes with 6GB of RAM for an extra breathing room when running resource-intensive apps.
Manufacturing process
A12Z is an older generation chipset based on the 7nm manufacturing process, while the newer A14 uses 5nm process. Smaller miniaturization allows chip makers to pack more transistors into a chip. Despite having a total of 16 CPU and GPU cores, the A12Z has only 10 billion transistors. The A14 with 10 CPU and GPU cores has nearly 12 billion transistors. Higher transistor count generally translates to better performance and more features. The A14 should also be more efficient than the A12Z. Even so, Apple claims that the A12Z is an optimized chipset with well-tuned performance controllers and improved thermal architecture.
Benchmarks
Benchmark results don’t directly indicate real-life performance, but they are decent measurements of the overall performance level.
Single-Core
As expected, the A14 Bionic has noticeable better performance with its higher clock, compared to A12Z in single-core operations. The normal 1.8GHz clock speed and 3.01GHz boosted clock speed should deliver respectable results.

Multi-core
Despite being an older 7nm technology, the A12Z offers better multi-core performance, because it has a couple of extra cores. The A14 has faster individual cores and smaller miniaturization, but it can’t compete with the octa-core A12Z.

Conclusion
When deliberating the decision to choose between iPad Pro (2020) and iPad Air (2020), it is important to compare the performance of internal hardware. It is important to remember that A14 doesn’t only offer faster cores and more improved manufacturing process. It also comes with 16-core Neural Engine frees up the CPU module from doing AI-based tasks. The Neural Engine can execute 11 trillion operations each second. There’s also the AMX block, which is a 2nd generation machine learning accelerator to ensure faster AI operations. A more improved image processor in A14 chipset offers enhanced photography results for iPad Air (2020). If you seek better raw multi-core performance, the iPad Pro (2020) with A12Z Bionic chipset is a better choice. The A14 has better GPU and AI modules. It means, you should choose iPad Air (2020) for gaming and AI-assisted photo editing.