iPhone Duo runs the A20 Pro, the same 2-nanometer chip Apple put in the iPhone 18 Pro and Pro Max. Apple’s press release lists a 6-core CPU up to 20 percent faster than the A19 Pro, a 7-core GPU up to 40 percent faster, a dual 16-core Neural Engine with twice the compute, and a custom vapor chamber, and it claims up to 35 percent better sustained performance than the iPhone 17 Pro.
The one thing the Duo’s chip does that the Pro’s does not is drive two displays at the same time. Apple’s iPhone Duo press release says a new display engine drives the inner and outer displays simultaneously.
What Apple says about the A20 Pro in each phone
| Spec | iPhone Duo (Apple press release) | iPhone 18 Pro (Apple press release) |
|---|---|---|
| Process | 2-nanometer | 2-nanometer, Apple’s first |
| CPU | 6-core (2 performance, 4 efficiency), up to 20 percent faster than A19 Pro | 6-core (2 performance, 4 efficiency) with Neural Accelerators |
| GPU | 7-core with Neural Accelerators, up to 40 percent faster than A19 Pro | 7-core, up to 40 percent faster than A19 Pro |
| Neural Engine | Dual 16-core, twice the compute | Dual 16-core, double the AI processing of A19 Pro |
| Memory bandwidth | Up to 50 percent more than A19 Pro | 50 percent more than A19 Pro |
| Cooling | Custom vapor chamber | Next-generation vapor chamber attached to the chip, 3x the surface area of iPhone 17 Pro’s |
| Sustained performance | Up to 35 percent better than iPhone 17 Pro | Up to 40 percent better than iPhone 17 Pro |
| Display engine | Drives the inner and outer displays simultaneously | Not mentioned |
The two releases describe the same chip with slightly different emphasis. Both give a sustained performance figure against the iPhone 17 Pro, up to 35 percent in the Duo release and up to 40 percent in the iPhone 18 Pro release, which also gives the vapor chamber three times the surface area of the iPhone 17 Pro’s. Apple has not said whether the Duo’s vapor chamber is the same design, or whether the chip is configured any differently.
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The one job the Pro does not have: two displays at once
The Duo has a 5.4-inch outer display at 1398 by 2034 pixels and a 7.6-inch inner display at 1878 by 2670 pixels. Both run ProMotion up to 120Hz with Always-On, at 1000 nits typical, 1600 nits peak HDR and 3000 nits peak outdoors, so the chip is feeding two high-refresh panels rather than one.
Several Duo-only camera features show why both displays need to be live at once. Duo Preview puts a live preview of the shot on the outer display for the subject while the photographer uses the inner one, Kid Cue plays animations on the outer display to hold a child’s attention, and Duo FaceTime lets nearby friends join a call on the outer display.
Whether that display engine is a distinct block on the Duo’s silicon or a capability the 18 Pro’s chip also has but does not use, Apple has not said.
What Apple has not published
- RAM in the Duo, or whether it matches the iPhone 18 Pro
- Whether the Duo’s vapor chamber matches the 18 Pro design or its surface area figure
- How the chip manages heat when the phone is closed and the two batteries and displays sit face to face
- Any benchmark for the dual-display engine itself
The Duo starts at $1,999 and ships Friday, October 23, with pre-orders on Friday, October 16, at 5 a.m. PT. For the chip’s debut in the iPhone 18 Pro, see the keynote live blog and our event recap.
