I just did a chat with Samsung and he said QC3.
Rahman UR: Hi, thank you for reaching out to Samsung Technical Support. How may I assist you?
John: Hi. Can you tell me which version of QuickCharge the S8/S8+ have?
Rahman UR: I will surely help you with that
John: ok, thanks
Rahman UR: I have checked with my resources.
Rahman UR: I see that the Galaxy S8 and S8+ has Quick Charge 3.0 Version.
John: ok. Thank you. Do you know if that's documented anywhere officially? No one can find it anywhere on the internet.
Rahman UR: Let me check if this is documented in our website.
Rahman UR: Unfortunately, the complete specifications of Galaxy S8 and S8+ are not yet updated in our Samsung website.
Rahman UR: Once the phone is released, you can view the Quick Charge feature in our Samsung website.
Rahman UR: However, I will help you with the web link to view the specifications of the phone in the future.
John: ok, thanks
Rahman UR: You're welcome.
Rahman UR: http://www.samsung.com/us/mobile/phones/galaxy-s/galaxy-s8-plus-64gb--verizon--midnight-black-sm-g955uzkavzw/
Rahman UR: Is the above link accessible?
John: Yes. although it just seems to take me to the regular S8+ page. I don't see any details there about the QC
Rahman UR: As of now, the complete specifications of the Galaxy S8+ is not yet update and will soon update after the release date which is 04/20/2017.
John: ok. thank you. I will look for them then.
Rahman UR: You're welcome. Is there anything else I can assist you with?
John: that's it. Have a nice day. Thanks