saphire r9 270x crash Radeon Wattman

hello, i have a problem with my video card, was fine,, but in these days , playing im  getting radeon wattmna default crash, then i can see  when supose is restore my default, my gpu clock stay on 450 mhz , instead 1100 mhz default OC, and if i change in over drive to 1000, or 990, o more, the gpu MHZ still on 450mhz , and keep crash , till i get restart my PC , and then the MHZ will be ok again.. is like when crash, get stucked on faulty MHZ.. im using 1.7.9.2 tried, new ones and older, and is the same, i was using msi after burner and is same problem.

 

help me please.

 

Motherboard: MSI Z87 MPOWER SP

Intel i5 4670k 3.4 ghz

coolermaster Hyper 212 evo

corsair vengeance 16gb

sapphire radeon r9 270x vaporX OC 2gb

corsair cx600m psu