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.

2 Answers 2


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.

  • Thanks, what I think is the GPU usage percentage on cgminer might not actually be the GPU usage anyway. Unfortunately, there is no reliable way to check the GPU usage in Linux distros, so I guess I'll just mine with one worker for now. Nov 6, 2012 at 22:52

I run 2 instances of cgminers because I have two cards one which performs better for SHA256 and the other performs better for the SCRYPT algorithm.

Effectively increased my hash rate by 10 percent doing this.

The only problem is when you use --auto-fan and (presumably) --auto-gpu

The nuisance is that cgminer version 2.4.1 is trying to control the fans of the GPU card that is turned OFF which causes unwanted rapid oscillations in fan speed as 2 cgminers are trying to control the fan of a single card.

To solve that, you need to go in G(PU)/C(hange)/#/A(uto)/F(an) where # is the number of the GPU card that is set to OFF in a specific instance of the cgminer.

This will prevent cgminer from accessing the fans of the card that is turned off.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.