Surprised ?
That card mines good. and it costs 50eu used.

This is my setting below.
HD5850 is the first one. The second one is HD5870 and the third and the fourth one is HD5970

All are HD5XXX series. and all are mining perfect

"intensity" : "20,20,19,19",
"gpu-engine" : "0-900,0-925,0-820,0-820",
"gpu-memclock" : "0-350,0-350,0-350,0-350",
"thread-concurrency" : "0,0,0,0",
"worksize" : "64,64,64,64",
"lookup-gap" : "2,2,2,2",
"shaders" : "0,0,0,0",
"gpu-threads" : "1,1,1,1",
"gpu-fan" : "60-100,60-100,60-100,60-100",
"auto-fan" : true,
"gpu-memdiff" : "0",
"gpu-powertune" : "20,20,20,20",
"gpu-vddc" : "0.000",
"temp-cutoff" : "95,95,95,95",
"temp-overheat" : "85,85,85,85",
"temp-target" : "65,60,65,65",
"api-mcast-port" : "4028",
"api-port" : "4028",
"expiry" : "28",
"failover-only" : true,
"failover-switch-delay" : "10",
"gpu-dyninterval" : "7",
"gpu-platform" : "0",
"log" : "5",
"no-pool-disable" : true,
"no-client-reconnect" : true,
"queue" : "2",
"scan-time" : "3",
"tcp-keepalive" : "30",
"temp-hysteresis" : "3",
"shares" : "0",
"no-submit-stale" : true,
"submit-stale" : "false",
"kernel" : "x13modold",
"kernel-path" : "/usr/local/bin"
}