Fast Charging toggle switch

[Asik]

Hi. I have a question. On the Samsung Galaxy S9 running Android Oreo, in Device-Maintenance>Battery>Advanced-Settings, there is an option to enable and disable Fast charging. 

I was curious to know what the difference would be, so I disabled it. And I noticed that there's no change in the charging speed, yet the phone never heated up as it would, when fast charging was enabled. Is this option still available in the new Android Pie with One UI?

For reference, I have attached a screenshot of that setting. 

[Vagabond]

Thanks dude! I was wondering why my phone w/ 25w adapter is saying fast charging! We have same option in Note10+.Guess we have to wait till 45w come to market then compare these two together.So far guys who tried both charger told me there's not much difference

[Asik]

Ohh I see. So the option exists in One UI. Glad to know that! And I'm glad this post helped you. Have a good one.

[BDTech]

You should just update.