I remember when i was mining with some 280x i have downloaded the wolf-x11Tahitigw64l8ku0.bin for more hashrate. Then i have used this in my config:
"algorithm": "darkcoin-mod",
"device": "all",
"xintensity": "128",
"worksize": "64",
"gpu-engine": "1080",
"gpu-memclock": "1500",
"thread-concurrency": "8192",
"gpu-threads": "2",
"gpu-fan": "60-100",
"gpu-powertune": "20",
"gpu-vddc": "0.0"
"failover-only": true,
"temp-cutoff": "94",
"temp-overheat": "90",
"temp-target": "80",
"gpu-memdiff": "0",
"kernel-path": "/usr/local/bin",
"auto-fan": true,
"expiry": "1",
"gpu-dyninterval": "7",
"gpu-platform": "0",
"hamsi-expand-big": "1",
"log": "5",
"no-pool-disable": true,
"no-client-reconnect": true,
"queue": "0",
"scan-time": "1",
"show-coindiff": true,
"temp-hysteresis": "3"
I hope this could help you. If not download this:
https://www.getpimp.org/downloads/pimp-amd.html
and use the settings above in pimp.
By the way dash.com is not a miningpool ^^