How to rotate Raspberry Pi 3 output display to Potrait.
1. Edit /boot/config.txt
# nano /boot/config.txt
Add the following line to the bottom of the line
display_rotate_1 <= this is to rotate the display output to 90 degrees
Ctrl + X and type Y <= to save the updated file
2. Allocate more memory to the GPU from 64M to 128M
# sudo raspi-config
In Raspberry Pi Software Configuration Tool, select Advanced Options.
Select "A3 Memory Split" change it from 64 to 128.
Press Tab and select <Ok>
