This year is the year Apple declared war on heat in its phones. Not only do the iPhone 17 Pro and iPhone 17 Pro Max have a new vapor cooling chamber, but the new design has also been crafted to help keep the phones as cool as possible — even during periods of sustained performance.
The switch to aluminum from titanium, a metal that reportedly caused overheating issues over the past couple of years, plays a key role in this. Likewise, the controversial raised camera bar (or forged plateau) houses more of the components. But have all these hardware changes actually worked?
We've just done a bunch of performance stress testing on iPhone 17 Pro Max and iPhone Air, and recorded the average temperature throughout the process — not just to see how hot both phones became, compared to other flagships, but also to test the overall performance stability.
iPhone 17 benchmark results
The first thing to remember is that the A19 Pro that powers the Pro Models and the Air is an astonishingly powerful chip, and benchmark tests show just how much more powerful it is compared to the A18 Pro chip from the iPhone 16 Pro Max. Both the Geekbench single-core and multi-core testing results reveal that across all three phones.
Geekbench |
3DMark Solar Bay Unlimited |
|
iPhone 17 Pro |
3,834 / 9,988 |
46.4 / 12,208 |
iPhone 17 Pro Max |
3,871 / 9,968 |
46.6 / 12,260 |
iPhone Air |
3,723 / 9,665 |
29.5 fps / 7,764 |
iPhone 16 Pro Max |
3,386 / 8,306 |
28.1 fps / 7,396 |
Galaxy S25 Ultra |
3,031 / 9,829 |
42.4 fps / 11,140 |
Galaxy S25 Edge |
3,129 / 9,916 |
39.26 fps / 10,343 |
Google Pixel 10 Pro XL |
2,322/6,286 |
N/A |
The iPhone 16 Pro Max came out of Geekbench testing with a single-core score of 3,386 and a multi-core score of 8,306, which was pretty darn high at the time. But with iPhone 17 Pro Max scoring 3,871 / 9,968 and the iPhone Air rocking in slightly behind at 3,723 / 9,665, it is clear that the new A19 Pro chip leaves last year's flagship in the dust.
The same goes for the 3DMark Solar Bay Unlimited graphics testing, with the iPhone 16 Pro Max scoring a fairly respectable (but not industry-leading) 28.1 average frame rate and a score of 7,396. The iPhone 17 Pro Max comes along and zooms ahead with a 46.6 average frame rate and score of 12,260.
The iPhone Air uses a version of the A19 Pro with only five GPU cores. It's marginally better than iPhone 16 Pro Max, with its 29.5 average frame rate and overall score of 7,764.
Stability and temperature
Faster performance typically means more heat is produced, especially over a sustained period of time. But did that actually happen? And is the sustained performance between the iPhone 17 Pro Max vs 16 Pro Max much improved?
To test this, we put the phones through the 3DMark Wild Life Extreme Stress Test, which simulates a 20-minute gaming session. We recorded the results after a single run through, then put the phones through a second 20-minute run immediately afterward to see how they performed over that sustained period of time.
Stability Score (20 mins) |
Stability Score 2nd (40 mins) |
Average temperature (40 mins) |
|
iPhone 17 Pro Max |
65.2% |
68.4% |
100.66 |
iPhone Air |
65.1% |
58.8% |
96.06 |
iPhone 16 Pro Max |
54.7% |
67.7% |
101.12 |
Galaxy S25 Edge |
41.9% |
44.3% |
95.78 |
Galaxy S25 Ultra |
49.3% |
52.5% |
100.32 |
The iPhone 17 Pro Max had the best stability scores overall, and there was a 11-point delta in round one with the iPhone 16 Pro Max. But the two phones were fairly close after round two. Meanwhile, the Galaxy S25 Ultra was way behind the iPhone 17 Pro Max with stability scores in the 50% range.
Interestingly, the iPhone Air came out with the lowest temperature of the three, with an average reading of 96.06 degrees Fahrenheit after 40 minutes. That's compared to the 100.66 degrees of the iPhone 17 Pro Max and the 101.12 degrees of the iPhone 16 Pro Max. The Galaxy S25 Edge came out the coolest of the phones we tested at 95.78 degrees.
That said, the iPhone Air does suffer a drop in stability after the 40-minutes test run. After a 20-minute Stress Test, there was only a 0.1% difference between it and the iPhone 17 Pro Max (65.1% vs 65.2%, respectively). But after the 40-minute run, the Air's score dropped to 58.8% while the 17 Pro Max's score rose to 68.4%. That would suggest the design changes made a noticeable impact on the sustained performance power.
Considering the additional power in the A19 Pro, and the fact that it's able to run slightly cooler and more stable than its predecessor, you might conclude that Apple has done something right with the iPhone 17 Pro design. That said, which new design feature this can be most attributed to isn't clear. It's probably a combination of all three, with the vapor chamber, aluminum unibody and forged plateau all playing their own part.
