I'm not sure what you're referencing by work discarded. Is that an error that your mining software is putting out? 

For that matter, what mining software are you using? I've heard mixed results with sgminer on the newer RX series cards.

Hey Esperians, I've created a pool specifically for mining Espers.  Head over to:

http://www.echoalphapool.com if you're interested in adding Espers to your mining portfolio.

Feel free to shoot me a line here, if you have any questions!