The A20 Pro chip in the iPhone 18 Pro includes a dual 16-core Neural Engine, 32 cores in total, which Apple says delivers double the AI processing of last year’s A19 Pro. It arrives five days before Siri AI enters beta with iOS 27 on September 14.
Apple’s answer to more demanding on-device AI was not one bigger engine but a second one, paired with Neural Accelerators integrated into the six-core CPU. We covered the rest of the chip in our story on the iPhone 18 Pro announcement.
What the dual Neural Engine actually is
The Neural Engine is the part of the chip built for the matrix math behind machine learning: image recognition, speech, and the on-device language models behind Apple Intelligence. Apple’s release describes the A20 Pro’s version as two 16-core engines rather than a single 32-core block.
Don’t miss the best of The Mac Observer
Set us as a preferred source and our Apple reporting ranks higher in your Google Search results and Discover feed — one tap, no account changes.
Apple has not said how work is split between the two engines, whether they run one model together or separate tasks in parallel. Apple also has not published a peak operations-per-second figure for the A20 Pro in its release, so “double the AI processing” is the only comparison on record.
The CPU’s integrated Neural Accelerators are a separate addition. Apple has not detailed what they handle versus the Neural Engine, though the naming suggests smaller AI operations that would otherwise run on the CPU cores. That is our reading, not an Apple statement.
Where Apple Intelligence uses the Neural Engine
Apple Intelligence runs on-device and, for heavier requests, on Private Cloud Compute. The on-device portion is where the Neural Engine matters, because it is the hardware running models without sending data off the phone.
The iOS 27 features Apple named in its release include:
- Siri AI, Apple’s new Siri, in beta in English at launch. French, Japanese, Korean, Portuguese and Spanish follow in October.
- Image Playground with photorealistic image generation.
- Hands-free Siri AI and Live Translation on AirPods 5, which require iOS 27 and an Apple Intelligence iPhone.
- Smart Focus subject tracking and upgraded Photographic Styles in the Camera app.
Apple has not said which of these rely on the Neural Engine rather than the GPU or CPU, and it has not said whether any iOS 27 feature is exclusive to the iPhone 18 Pro. If the doubled engine unlocks anything on its own, Apple did not name it.
Why doubling AI processing matters
Doubling on-device AI processing generally buys two things: responses that arrive faster, and larger models that fit within the same time budget. This is analysis on our part, since Apple has not published benchmark comparisons for the A20 Pro.
It also fits the rest of the chip. Apple says the A20 Pro has 50 percent more memory bandwidth than the A19 Pro, and bandwidth is often the limiting factor for on-device language models rather than raw compute.
Greg Joswiak, Apple’s senior vice president of Worldwide Marketing, put intelligence alongside camera, performance and battery as the areas Apple focused on this year, according to Apple’s press release. The Neural Engine is the hardware side of that claim.
Pre-orders for the iPhone 18 Pro open Saturday, September 12 at 5 a.m. PT, with availability on Friday, September 18. iOS 27 arrives as a free update on September 14, and we have a guide to what to expect from the iPhone 18 Pro pre-order process. You can also revisit the full keynote in our Apple event live blog.
