Massive Galaxy Note 9 heatsink will let you use desktop mode without a dock
One possible reason for Samsung's decision to use valuable phone real estate for cooling is that the Galaxy Note 9 is rumored to allow desktop experience without the need for a dedicated DeX docking station. Besides the ports that let you connect your Galaxy device to an external monitor and peripherals, both of Samsung's solutions – the DeX Station and DeX Pad have cooling fans as an additional feature. This allows the smartphones to work for an extended period of time without overheating, but if the Note 9 is to be able to do the same without fans keeping its temperature in check, it makes sense to have a beefier cooling solution. There will be one limitation of the direct connection, however, users will be able to use a maximum of 5 applications at the same time, down from the 20 you can have opened while the device is on a DeX dock.
Of course, the improved cooling will be great when using heavy applications for a long time, especially during a "heated" session of Fortnite.
This is probably one of the last few pieces of the Galaxy Note 9 puzzle we're putting together before the official announcement on August 9th.
source: SamsungMobile.news via MSpoweruser