In order for you to play X-Plane 11 on Linux with minimal graphics settings, your computer must meet the following requirements
Operating System:
Varies, Ubuntu 16.04LTS tested
Processor (CPU):
Intel Core i3, i5, or i7 CPU with 2 or more cores, or AMD equivalent
Memory (RAM):
8 GB RAM
Graphics Card:
video card from NVIDIA or AMD w/512 MB VRAM with proprietary driver
Network:
Broadband Internet connection
Storage:
20 GB available space
Sound Card:
Default
In order to play X-Plane 11 on Linux with maximum graphics settings, you need a computer with a configuration no worse than the following
Operating System:
Varies, Ubuntu 16.04LTS tested
Processor (CPU):
Intel Core i5 6600K at 3.5 ghz or faster
Memory (RAM):
16 GB RAM
Graphics Card:
video card from NVIDIA or AMD w/4 GB VRAM with proprietary driver
Network:
Broadband Internet connection
Storage:
65 GB available space
Sound Card:
Default