Your TC is too low. Minimum TC should be at 10240+. If i run anything under 10k i get HW errors.
I run my 10 270s @ TC 24k. You need to add that setx GPU_MAX_ALLOC_PERCENT 100 command.
Anything other than 8192 gives me error -61 and cgminer won't start. Even with the `setx GPU_MAX_ALLOC_PERCENT 100` added
if your using cmd, just run those commando first before starting cgminer
-> setx GPU_MAX_ALLOC_PERCENT 100
-> setx GPU_USE_SYNC_OBJECTS 1
-> /path/to/cgminer.exe --scrypt -o {pool stuff} -u {username} -p {pass} --thread-concurrency 8192 --gpu-engine 925 -I 13