doc, regarding loki-turtle , i have 2 gfx in one system, i checked your youtube video. How do i limit this mining to one GFX?

i tried changing specific config file for loki-turtle by adding:

"gpu_conf" :
[
   { "id" : 1, "intensity" : 60 , "worksize" : 8, "threads" : 2},
   
]

but miner instantly shuts down if i add this to cfg file