Become a MacRumors Supporter for $50/year with no ads, ability to filter front page stories, and private forums.

pshufd

macrumors G4
Original poster
Oct 24, 2013
10,555
14,810
New Hampshire
I used to run a 2014 15 inch MBP in the office hooked up to two QHD monitors with the lid closed and I was apparently using a 65-watt charger from a 13-inch MBP. This worked fine as I guess the power draw from using the laptop was below 65 watts so that the laptop charged while in use.

I have a 2015 15 inch MBP with AMD and it's using the Discrete Graphics (it needs to to support 2xQHD + internal) and I noticed the charge percentage dropping. So the 2015 + AMD uses more than 65 Watts. I plugged the 85 Watt charger in and it's rising again.

Just a funny observation. It is very nice having the discrete graphics but it looks like it definitely uses a non-trivial amount of power.
 
I used to run a 2014 15 inch MBP in the office hooked up to two QHD monitors with the lid closed and I was apparently using a 65-watt charger from a 13-inch MBP. This worked fine as I guess the power draw from using the laptop was below 65 watts so that the laptop charged while in use.

I have a 2015 15 inch MBP with AMD and it's using the Discrete Graphics (it needs to to support 2xQHD + internal) and I noticed the charge percentage dropping. So the 2015 + AMD uses more than 65 Watts. I plugged the 85 Watt charger in and it's rising again.

Just a funny observation. It is very nice having the discrete graphics but it looks like it definitely uses a non-trivial amount of power.
At full load, the 15" MBP will discharge the battery even when connected to the 85W power adapter.
 
Register on MacRumors! This sidebar will go away, and you'll see fewer ads.