iPhone 18 Pro has the best power consumption and lowest heat among competitors
Tests of the iPhone 18 Pro and iPhone 18 Pro Max showed significant progress by Apple in energy efficiency and cooling. Under gaming loads, smartphones with the A20 Pro consume less power than current Android flagships.
iPhone 18 Pro Max consumes less
Geekerwan conducted a detailed test. In Genshin Impact at 60 fps and 884p resolution, the iPhone 18 Pro Max consumed an average of 3.4 W, while the compact iPhone 18 Pro used 3.3 W. For comparison, the iPhone 17 Pro Max required about 3.9 W, and Android flagships based on the Snapdragon 8 Elite Gen 5 and Dimensity 9500 needed approximately 4,6-4,8 W.
Excluding the approximately 0.6 W consumed by the display and network connection, the power consumption of the new iPhone’s computing section dropped by about 15% compared to the previous generation. During this test, the surface temperature remained within 38-39 °C.
Under heavier load, the reserve capacity of the new cooling system allowed the A20 Pro to operate at a noticeably higher power consumption. In Arknights: Endfield at 1036p resolution after 30 minutes, the iPhone 18 Pro Max maintained a frame rate close to the target 60 fps while consuming 5.9 W at a surface temperature of 43.5 °C.
In Neverness to Everness at a resolution of 792p, the smartphone averaged 58.9 fps. Power consumption reached 6.4 W, yet the chassis heated up only to 42.6 °C. In Wuthering Waves, the result was less favorable: at 748p resolution, the frame rate hovered near 50 fps and trailed behind the OnePlus 15, although the iPhone’s temperature remained below 42 °C.
New cooling system
A separate stress test allows you to assess the capabilities of cooling. Geekerwan compared the iPhone 18 Pro Max with last year’s iPhone 17 Pro Max, OnePlus 15, and the gaming iQOO 15 Ultra with a built-in fan.
| Smartphone | Power consumption | Temperature |
|---|---|---|
| iPhone 18 Pro Max | 5.9 W | 44.3 °C |
| iPhone 17 Pro Max | 5.4 W | 45.2 °C |
| OnePlus 15 | 6.1 W | 47.2 °C |
| iQOO 15 Ultra, fan off | 5.9 W | 47.2 °C |
| iQOO 15 Ultra, fan at maximum | 7.3 W | 46.2 °C |
Thus, at the same power consumption of 5.9 W, the iPhone 18 Pro Max was 2.9 °C cooler than the iQOO 15 Ultra with the fan turned off. The OnePlus 15 managed to maintain a slightly higher power level of 6.1 W but heated up to the same 47.2 °C.
The built-in fan of the iQOO 15 Ultra still gives the gaming smartphone an advantage in maximum power dissipation: with it enabled, the device was able to operate at 7.3 W. Therefore, the results do not mean that Apple’s passive cooling is more efficient than iQOO’s active system. The test shows something else: at comparable power levels, the iPhone is able to maintain a lower chassis temperature.
Why the A20 Pro runs cooler
Apple simultaneously redesigned the A20 Pro itself and its thermal system. The 2-nm processor uses a new layout inspired by the M-series chips: the die and RAM are now placed side by side rather than stacked. As a result, memory no longer sits between the processor and the cooling system, and the A20 Pro now makes direct contact with the vapor chamber.
The area of the new vapor chamber is approximately three times larger than that in the iPhone 17 Pro system. Apple states that, combined with the redesigned processor layout, this enables up to 40% higher sustained performance.
An additional Geekerwan experiment indirectly confirms that the A20 Pro is already near its maximum CPU potential at normal temperatures. After extreme cooling with liquid nitrogen, the Geekbench score increased by only 0.76% in the single-core test and by 2.49% in the multi-core test. For the A19 Pro, the gains were 5.77% and 10.06%, respectively; for the Snapdragon 8 Elite Gen 5 – 5,04% and 12.62%; and for the Dimensity 9500 – 9,14% and 12.66%.
This does not mean that standard iPhone cooling is equivalent to liquid nitrogen: Geekbench runs relatively short tasks with pauses between them. However, the result shows that additional cooling barely increases the short-term CPU performance of the A20 Pro.
The chassis will not always be cooler
Results from other tests reveal an important nuance. GIGAZINE compared the iPhone 18 Pro and iPhone 17 Pro in AnTuTu and found a maximum display-side temperature of 41.0 °C for the new model versus 40.1 °C for the predecessor. On the back panel, the values were 39.9 and 39.1 °C, respectively.
At the same time, iPhone 18 Pro exhibited stronger heat spread across the entire back panel, whereas iPhone 17 Pro had a hot zone more concentrated near the camera. This is expected behavior for an evaporative chamber: its goal is not to keep the chassis cool under any load, but to distribute heat faster over a larger area and prevent the processor from overheating for longer.
In the same tests, GIGAZINE reported that the iPhone 18 Pro significantly outperformed its predecessor in performance. In Geekbench 7, it scored 4030 and 11,507 points in single-core and multi-core modes, compared to 3301 and 9185 points for the iPhone 17 Pro. The GPU result increased from 44,062 to 61,566 points.
Initial tests ultimately show that the main change to the iPhone 18 Pro’s cooling system is not simply a reduction in temperature. The A20 Pro can handle the same gaming load with lower power consumption, and for heavy, sustained tasks, the new design allows the processor to operate at a higher power limit without a corresponding rise in chassis temperature.
