Look for DiamondTahiti.elf in downloads area. Rename to match your current *.bin in sgminer. Restart sgminer to use new bin.
NOTE: you may have cooling issues, this kernel runs GPU very hard, gotta love Utah winter cold here but will crash GPU if it gets too hot.
Still have to run a space heater but last year no added heat needed mining scrypt ...
Thanks, Utah. I tried this and got an additional 5 mh/s out of a 280x and yes, it runs hotter. I have fans running at 100% to cool it and its running about 3 degrees C hotter but still only 71 degrees C. I am not overclocking the card at the moment. The 280x seems to deliver less performance for the additional power used when overclocked - power consumption exceeds performance improvement.
I can try this on the R9 290 but those already run ridiculously hot and I am hesitant. I fried one PSU/PCI-e cable already pushing them too hard. I am running out of power supplies and frankly, given the value of BTC right now, I don't want to increase my investment right now.