That looks like it just might be your CPU voltage limit. I don't think you should go any higher than that, on air at least.
When do you get your new thermal paste, I would recommend researching the best methods before you apply. Find whatever works best for your setup (different HSFs/mounting systems can create different patterns. Or you could spread it on thin with your finger (in a rubber glove if you have one).
Depending on the type of surface you are applying it to, different levels of viscosity are recommended. Higher viscosity is better for surfaces with more grooves, low viscosity is better for very flat surfaces (lapped CPU/HSF).
And yeah I can't seem to crank it up more than that. I increased frequency by 2 more and computer crashes on prime95.