Overclocking older CPU and GPU. What is the best settings for me?

DOGEsandstorm

Estimable
Jul 18, 2015
2
0
4,510
So my problem is, that i was interested into overclocking, and i tried overclock CPU and GPU on nVidia Control Panel. For the first time i've tried to Overclock nVidia GT520 1GB. I checked overclock perfomance on Counter Strike:Global Offensive. All the time game runned bit faster but oftenly i felt huge frame rate drops. So i said to myself: ''nevermind, lets try out CPU''. My CPU is 2,7 GHz AMD Athlon64x2. Maximum lock was 2,997 , because if i went over 3,000 , control panel and whole pc freezed. So after CPU overlocking i went to play Unturned. Game Perfomance was few additional frames. I was happy until everything freezed, computer started screaming as hell and BAM! Blue Screen... I'm not a proffesional overlocker , only begginer so please help me!
Sorry for bad english :)