In the password field add this

-t 1

eg

-o stratum+tcp://xevan.mine.zpool.ca:3739 -u YOUR_BITCOIN_ADDRESS_HERE -p c=BTC,d=0.003 -t 1

See the end of the command line, this tells Awesome Miner to use the first GPU only.

All of this below is put in the password field

c=BTC,d=0.003 -t 1

c=BTC << this is a payment symbol (bitcoin), it's used with my bitcoin wallet address

d=x.x << this sets the difficulty for the GPU

Update: The -t command disables all other GPU's, I am looking for a fix.