In order for you to play X Rebirth on Linux with minimal graphics settings, your computer must meet the following requirements
Operating System:
SteamOS (64-bit) or Ubuntu 14.04 (64-bit)
Processor (CPU):
Intel i-Series at 2GHz or AMD equivalent
Memory (RAM):
8 GB RAM
Graphics Card:
Vendor proprietary drivers, Nvidia GT500 series with 1GB RAM or better, ATI 5870HD with 1GB RAM or better
Storage:
8 GB available space
Sound Card:
OpenAL Soft compatible
In order to play X Rebirth on Linux with maximum graphics settings, you need a computer with a configuration no worse than the following
Operating System:
SteamOS (64-bit) or Ubuntu 14.04 (64-bit)
Processor (CPU):
Intel i5 (Quad) or i7 at 2.5GHz or AMD equivalent
Memory (RAM):
12 GB RAM
Graphics Card:
Vendor proprietary drivers, Nvidia GT600 series with 1GB RAM or better, ATI 6850HD with 1GB RAM or better
Storage:
12 GB available space
Sound Card:
OpenAL Soft compatible