Maximum number of GPUs

configname: CONFIG_VGA_ARB_MAX_GPUS

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Maximum number of GPUs
In linux kernel since version 2.6.34 (release Date: 2010-05-16)  
Reserves space in the kernel to maintain resource locking for
multiple GPUS. The overhead for each GPU is very small.