Another dumbass question: Has anyone run multiple instances of miner clients and had it stay stable. I want to use seperate cards in same box so I can try Vertcoin. I realize I might have to upgrade memory capacity for that box. I know cgminer has an option to select cards to use ... just have not dug into it yet and do not want to make my mining box unstable trying this.
I use a separate instance of cgminer for every card, it works fine. Just specify the device and device platform in your code. This is the only way to run different cards at different settings on the same box anyways, as far as I know. You will need to run "cgminer -ndevs" once to check what device and platform numbers your cards are listed as, then edit your code to include "--device-platform X --device Y" where x and y are the id numbers you got when you ran cgminer -ndevs in the previous step. For example, you might have device 0 and device 1 both on platform 0.
I am doing this from memory, I can't get into my boxes at the moment to double check my code syntax so if I just made any errors please do correct me guys.