Renders of what the iPhone 17 Pro and Pro Max could look like: Render source – AppleInsider
The iPhone 17 Pro and Pro Max are expected to get a much better cooling system, with vapor chamber technology rumored to keep the A19 Pro running at top performance for longer.
Apple’s chip designs used in the newest iPhone models are fast, but can be easily affected by heat. After processing a task for a prolonged period of time, or in hot environmental conditions, the chip will often throttle itself to minimize damage.
For the iPhone 17 Pro and iPhone 17 Pro Max, this may not be the case because of an important addition. In a Weibo post, serial leaker “Instant Digital” claims the models will be using vapor chamber cooling.
It is claimed that the thermal management change in the new models will not be prone to slowing down. The leaker says that the system will dissipate heat, and that the stronger thermal management will not reduce the clock speed under heavy loads.
In follow-up posts, there are also mentions of a possible removal of the SIM card slot in China. The overall designs of the smartphones will be fairly static, the leaker adds, with the notch and bezel sizes likely to remain the same as the iPhone 16 Pro generation.
How vapor chamber cooling works
Typical thermal management systems involve drawing heat away from a source, and then dissipating it in some way. This can be via a heatsink in a computer, but for a phone or tablet, the space constraints makes it a lot harder to achieve.
There’s no space to circulate air or exhaust it in an iPhone or iPad, leaving Apple with little room to maneuver. The tightly packed hardware situation and the potential danger of burning a user’s hand with a hot enclosure means Apple has to be very modest with how hot a chip can run, and so throttling takes place.
In vapor chamber cooling systems, a sealed chamber is fitted above the chip, designed in a way that spreads over a larger area, away from the chip itself. The chamber contains a liquid, which handles thermal transit.
The liquid is heated up near the chip, turning it into a vapor that spreads throughout the chamber, quickly shifting heat. As it condenses, the vapor changes back to the cooler liquid, which enters a wick structure and is returned to a position near the chip, ready to be heated again.
The technique isn’t new to smartphones, as some premium Android devices have gone on sale using the technique. If the rumors are true, this would mark the first time Apple will use the system in its flagship product.
A repeat cooling rumor
Weibo leakers such as Instant Digital are not necessarily the most accurate source for future device claims. They frequently repeat rumors heard from elsewhere, and frequently get things incorrect.
However, the claim of a vapor chamber system is still plausible — and it’s not the first time we’ve heard it.
The earliest rumors date back to January 2021, with analyst Ming-Chi Kuo reporting that Apple was “aggressively” testing vapor chamber thermal systems for use in an iPhone and other hardware. By August 2024, Kuo insisted that it could end up being used in the iPhone 17 Pro Max.
In January, a rumor from MyDrivers was picked up, refining the claim to include vapor chamber cooling on both Pro models in 2025.
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