how much should i overclock my xfx 7870 tahiti LE

LshortyTV

Honorable
Oct 4, 2013
33
0
10,530
I am going to be overclocking my XFX 7870 Tahiti LE and I was wondering how much should I overclock it. under full load (MSI konbuster stress test) after 30000 frames its max temp was 59 degrees with the fan speed on 50%. I would like to overclock it to get better frame rates on new games such as battlefield 4. its default specs are core clock: 1000MHz
memory clock: 1250MHz

how much should I increase it by so it will be better but also that it will still be safe to use. also do I have to change the core voltage or power limit when overclocking