Hi guys. With 10.0.1642.5 amdocl.dll from 15.4 beta win32 in sgiminer folder my 5850 hash  around 1.6 mh/s. (my system win 7 64bit  driver installed 14.7 version 14.200.1004.0
 and this config
           r9 280x, 5850

make a bin for r9 280x with system keep it. Then make a second bin with amdocl.dll from 15.4 32bit. Make sure you have the same intesity. something like this