With the iPhone 18 Pro, the surface area of heat dissipating components has been tripled. Apple’s emphasis is not on “getting faster,” but on “staying fast.” It explains that compared to the iPhone 17 Pro, the performance is up to 40% higher and lasts longer.
Let’s take a look at what this difference means.
Two things have changed
There are two main changes to the cooling area that Apple has mentioned.
| What has changed | Apple’s explanation |
|---|---|
| vapor chamber | Replaced by the next generation, with triple the surface area. Adopts material with high thermal conductivity |
| How to assemble the chip | Packaging inspired by the M series. Place silicon die and memory side by side to improve heat flow |
A vapor chamber is a component that transports heat by converting the liquid inside into gas. This is a mechanism that has been used in gaming PCs, etc., and was adopted in iPhones starting with the iPhone 17 Pro.
Apple only says that it has “three times the surface area,” but does not specify what it compares to. From the expression “next generation,” it is natural to think that it refers to the immediately preceding generation.
Another is “don’t put memory on top of the chip”
This is often overlooked, but it may be the most effective. Here’s Apple’s explanation:
By placing the silicon die and memory side-by-side, the A20 Pro chip’s packaging dramatically improves heat flow. Cooling performance has greatly improved.
Previous iPhones were built with memory layered on top of the chip. At the cost of saving space, things that produce heat are piled up in one place.
This time, I arranged the memory horizontally. Since the heat source is separated, it is easier to dissipate the same amount of heat. The point is that it’s not just about making the vapor chamber bigger.
“40% faster” and “40% higher performance lasting longer” are two different things.
Similar numbers appear twice in Apple’s description. The meaning is completely different.
| Apple’s expression | meaning |
|---|---|
| Up to 40% faster than iPhone17 Pro (graphics performance) | Instantaneous speed. Benchmark numbers |
| Up to 40% higher performance lasts longer | The time it takes for the speed to drop. This is where cooling works |
When smartphones get hot, they purposely reduce their performance to prevent them from breaking down. This is the true cause of phenomena such as movement becoming jerky when playing a game for a long time, and image quality decreasing when recording a video continuously.
Even with better cooling, the instantaneous maximum speed remains the same. What changes is how many minutes you can continue at that speed. That’s what Apple is referring to when they repeatedly say “long lasting.”
How accurate were the drawings you read two months ago?
On June 28th, this site announced that the memory layout would change based on the leaked A20 Pro board drawings. Check the answers.
| Contents reported on June 28th | In the announcement |
|---|---|
| Memory is placed on the side of the chip instead of on top | ◯ Official explanation: “Arranged side by side” |
| The heat source is dispersed, increasing the degree of freedom in heat radiation. | ◯ “Dramatically improved heat flow” |
| Focus is on sustained performance rather than peak performance | ◯ “40% higher performance lasts longer” |
| Cooling mechanism remains almost the same as iPhone17 Pro | × Renovated to next-generation product with three times the surface area |
Three were hits and one was misses. What was wrong was that the cooling mechanism would remain the same, which means that Apple went further than expected.
Heat dissipation should have been improved just by changing the memory placement, but in addition to that, we also redesigned the vapor chamber. I can read that there was a reason to do both.
Why did we put so much effort into cooling?
Apple’s explanation explains why.
Run more demanding games and larger, more complex AI models on your device for longer than ever before.
The premise is that the AI model will continue to run on the device.
Siri AI has a mechanism that sends heavy processing to Apple’s servers, and there is a limit to the number of times it can be used per day. The wider the processing range on your device, the more you can use it without worrying about the upper limit.
Enhanced cooling is positioned as the foundation for long-term operation of AI. Unlike cameras and displays, it’s a part that you can’t see, but that’s why Apple devotes an entire section to explaining it on its product page.
This is where replacing your car makes a difference
The following situations are where using the product makes a difference, rather than just looking at the numbers in the catalogue.
- When playing the game for more than 30 minutes (movement slows down in the second half)
- When taking long shots in 4K or ProRes (difficult to stop during shooting)
- When using AI functions continuously (processing is less likely to slow down)
- When using in summer or outdoors (heat tends to build up easily)
On the other hand, there is almost no noticeable difference when you use it only to check email or SNS. The evolution of cooling is more effective for people who continue to apply load.
Pre-orders for the iPhone 18 Pro series will begin on September 12th (Saturday) at 9pm, and will be released on September 18th (Friday). The details of the presentation are summarized here.
Source: Apple
Source: iPhone Mania
