Better or worse to mine multiple workers on one machine? I use cgminer on Ubuntu 12.10 to mine bitcoins in the 50BTC pool. I have three workers set up. If I run multiple instances of cgminer, each targeted at their respective workers (1, 2, and 3), would this increase profits or just waste power?
I notice this because cgminer only uses about 80-90% of my GPU (Radeon HD 6570) anyway.
You ought to test the setup on the machine you will be using. Generally the mining software should efficiently use the entire GPU, but it might happen that it will not and actually running two instances at the same time will allow you to tap into more computing power. But again, check your speed while running one or more instances and see which one gives you more total speed.