The Samsung Note9 Shows How Important Smartphone Cooling Has Become

Photo: Sam Rutherford, Gizmodo

Recently, sentiment has been growing that smartphones aren’t as exciting as they used to be, and to a certain extent, that’s true. Smartphones have been getting faster, their cameras have gotten sharper, and their displays have gotten bigger, but at the same time, they are more or less the same rectangular pocket computers we’ve been using for the last four or five years.

However, starting in late 2017, we’ve also seen the emergence of several gaming phones such as the Razer Phone, the Nubia Red Magic and the Asus ROG Phone. Phones focused on playing popular, but taxing, mobile games such as Fortnite.

With the increased focus on graphics and gaming also comes a bigger demands on other aspects of the device as well. That’s because aside from battery life and performance, one of the biggest limiting factors for smartphones is cooling. Typically, devices are forced to cram components such as dual rear cameras, wireless charging and fingerprint sensors into super thin bodies, which leaves very little room for moving heat around.

More heat, consequently, means the CPU can’t process as quickly, effectively throttling the device. To address this issue on the new Galaxy Note9, Samsung made quite a bit of noise about how it tripled the size of its heat spreader from the 100mm2 unit used in the Galaxy Note8 and Galaxy S9, to a 335mm2 unit in the Galaxy Note9. Samsung says it has also increased thermal conductivity by using a new carbon fibre interface to better channel heat away from the phone’s processor.

That big copper thing at the top is part of the heat spreader (Image: Samsung)

And while this might sound like crap, it does have an effect! When I reviewed the Galaxy Note9, I set up a special test to see how well the Note9's newly enlarged heat spreader performed vs the smaller versions used in its older siblings.

First, using phones that had been resting at idle, I ran Geekbench 4 and 3DMark Slingshot Unlimited to get a sense of the two phones’ baseline CPU and graphics performance. Initially, because both the Note9 and S9 use the same Qualcomm Snapdragon 845 processor, scores were quite similar, with the Note9 scoring 9012 in Geekbench and 5021 in 3DMark, while the S9 scored 8414 and 5033, respectively.

Then I ran a series of tests on both phones designed to strain their performance, which included running Geekbench and 3DMark several more times, playing a few rounds of Fortnite, and downloading multiple torrents, all without taking a break in between. Once I was done, I reran Geekbench and 3DMark to see how much each phone’s performance had dropped.

In Geekbench 4, the S9 sturggled quite a bit, as its benchmark score dropped by more than 25 per cent to 6171. Meanwhile, the Note9 fared much better at 8053, a decrease of around 10 per cent. Not bad! It seems as though that heat spreader is doing something.

However, when it came to 3D Mark Ice Storm — which measures GPU performance — differences between the Note9 and S9 weren’t quite as significant, with the Note9 falling to 4974, which as practically the same as the S9's 4923.

That’s a decrease of around two per cent for both, which suggests that either the phones hadn’t been pushed hard enough, or that their processors had hit peak performance without being limited by thermal constraints. If I had to bet, my guess would be on the latter.

Asus made a cooler for its upcoming gaming phone. (Image: Asus)

Regardless, the test shows that at least when it comes to CPU performance, heat management is going to play an important role in ensuring our phones run fast, and continue to do so during prolonged loads.

Also, it isn’t just Samsung that is thinking this way, because on the ROG Phone, Asus went out of its way to make a tiny cooler with built-in fans that plugs into one of the phone’s USB-C ports to help keep heat down, in addition to installing a massive copper heat spreader with a carbon cooling pad.

While it’s hard to say if Asus’ solution works, since the device hasn’t been released, it’s clear smartphone companies are thinking a lot more about cooling than they did before.

Trending Stories Right Now