I installed the last nvidia driver and ccminer x15 still not working on my GTX690
Works for me. Getting around 5500 khash/s with a pair of GTX690's. I'm using an old driver though. GPU utilization fluctuates between 70% and 99%.
What is your command line?

Pretty much a copypaste of the test.bat file that was included in the binary package. Which was:
x86\ccminer.exe -a x15 -o stratum+tcp://bbl.suprnova.cc:3663 -u Miyu.1 -p x
So even this doesn't work for you? My GPU kernel delay (TdrDelay) was modified to 40s, don't know if this helped here.