How to set 720p?

[Lifeless Grace]

Hi everyone,i want to use linux with gui,but i have monitor with 900p res,and,you know, i can't use 1080p.
I read before that Mali400 does not support 720p on Linux systems,is it true? And if not-how can i setup resolution? 
P.S. Remix OS is very laggy so i don't want to use it/

Pine A64 2GB