709: Steel-Cable Insurance

What It Covers

ATP episode 709 covers the iPhone 18 Pro and iPhone Duo hardware analysis, including A20 Pro and M6 chip benchmark comparisons, variable aperture camera mechanics, foldable device usability tradeoffs, Apple Pencil compatibility gaps on the Duo, iOS 27 feature omissions, John Turnus's leadership style as new Apple CEO, and a St. Jude Children's Research Hospital fundraising campaign for September.

Key Questions Answered

• •A20 Pro single-core performance: The A20 Pro chip in the iPhone 18 Pro scores 24% better in single-core CPU performance than the A19 Pro and 11% better than the M5 iPad Pro, previously the single-core leader. GPU metal benchmark scores came in at 38% above the A19 Pro, aligning precisely with Apple's stated 40% gaming performance claim. This makes the A20 Pro the strongest single-core performer across Apple's entire current lineup, including desktop chips.
• •M6 chip generational gains: Preliminary Geekbench data shows the M6 delivers 10% better single-core and 35% better multicore CPU performance over the M5, with GPU scores 25% higher. These are unusually large year-over-year gains for a non-suffix chip. When comparing the M5 Ultra to the M5 Max, the Ultra shows roughly 60% better multicore performance, though benchmark parallelism limitations mean real-world rendering workloads may tell a different story than synthetic scores.
• •Variable aperture equivalents on iPhone 18 Pro: The iPhone 18 Pro's widest aperture of f/1.48 translates to approximately f/5.2 on a full-frame sensor, while the narrowest f/4 setting equals roughly f/14 full-frame equivalent. Apple's camera software defaults to f/1.8 for most shots, reserving the wider f/1.48 for low-light conditions. Third-party apps can access the full continuous aperture range beyond the four presets Apple exposes natively, including smooth aperture transitions during video recording.
• •Straight aperture blades and starburst rendering: The iPhone 18 Pro uses straight-edged aperture blades rather than rounded ones, a deliberate optical choice. Straight blades produce sharper, more defined starburst effects on point light sources, while rounded blades produce softer, less defined starbursts. The number of starburst rays equals twice the number of aperture blades. Stopping down to a higher aperture value in mixed artificial lighting also reduces sensor banding caused by LED flicker during video capture.
• •iPhone Duo developer tooling gap: As of recording, Xcode 26.1 beta — which includes the iPhone Duo simulator — has not yet shipped, despite the device launching imminently. Xcode 26.2 beta released instead, explicitly noting it does not include Duo development support. This leaves developers unable to test or adapt apps for the new form factor before customers receive devices. A parallel is drawn to Apple's past policy change blocking App Store reviews from beta iOS builds, suggesting a similar review moratorium for Duo apps would be fair.
• •iPhone Duo MagSafe and accessory compatibility: The Duo's short, wide aspect ratio means many existing MagSafe accessories — including wallets and battery packs — will either extend beyond the device's edges or sit atop the camera plateau, preventing flat contact. The magnetic alignment circle may fit, but the physical footprint of standard MagSafe accessories was designed around taller iPhone proportions. Buyers should verify Duo-specific compatibility before purchasing accessories rather than assuming standard MagSafe labeling guarantees a usable fit.
• •Apple Pencil support on iPhone Duo is limited: The iPhone Duo supports only the USB-C Apple Pencil, which lacks pressure sensitivity, not the Apple Pencil Pro. The Pencil Pro requires magnetic attachment for both pairing and charging, and the Duo provides neither. A rumored bespoke pressure-sensitive pencil designed for the Duo was reportedly canceled during development, with the USB-C model serving as a fallback. Third-party stylus makers are positioned to fill this gap with Duo-optimized pressure-sensitive options.