help overclocking

I tried AIDA64 View: https://i.imgur.com/ffcicEu.jpg and my mhz was between 4500-5000 does that mean its not stable? but at Cinebench R15 core mhz was at 5000 Mhz stable View: https://i.imgur.com/k001J9q.png so does that mean my i7 9700k is stable? or should I increase the V