iPhone 18 Pro's Redesigned Vapor Chamber Triples Cooling Surface Area

Apple today announced a redesigned thermal system for iPhone 18 Pro and ‌iPhone 18 Pro‌ Max, built around a next-generation vapor chamber with three times the surface area of the one in iPhone 17 Pro.

The new vapor chamber constantly cycles deionized water throughout the system for significantly improved cooling performance, allowing the A20 Pro chip to sustain higher performance for longer under heavy workloads.

Apple redesigned the silicon packaging with "custom packaging inspired by our M-series chips," placing the silicon die and memory side by side rather than stacked, which removes the memory from the chip's thermal path and lets the A20 Pro connect directly to the vapor chamber.

According to Apple, the combination of the new packaging, new thermal materials, and the larger vapor chamber delivers up to a 40% gain in sustained performance over the previous generation, which the company calls the highest sustained performance yet in an iPhone.