Here is an absolutely wild idea. OC Scanner sucks donkey. It is merely a quick way to see if your card can even handle being out of spec easily.
Some folks on here also dont seem to understand, your video card has absolutely ZERO overclocking guarantee. If your card cannot do as much as even 5mhz increase in core, but still hits the expected BOX labeled clocks, your card is still considered 100% functional and proper.
curve lock overclocking, plus forcing higher temps via limiting fan speed will find your limits much quicker. And overall, great way to do overclock profiles per game, as some games just do NOT like certain frequencies for whatever reason or another.
Why force temps to rise up? you find the best average overclock you can while running say, 80*C max core, plop the overclock into a profile, then let the fan sing in normal usage and never have an issue during normal gaming GENERALLY.
Especially since nearly all the 3xxx series do really well thermally.
Riding the edge of clocks and cooling means as soon as the room gets a little hotter, the graphics card starts getting super picky. Screw that, I will always be more satisfied with a 10% overclock than a 15% overclock even 90% of the time. As much as I like max numbers, I like a smooth no-reboot experience!