Core Voltage vs GPU clock speed (Memory clock / Core clock)?

[Eclipse95]

Hi guys, I just started to learn how to overclock a graphic card recently.
I've got a ATI Radeon HD 6850 (Sapphire version)
Few days ago, I watched some guides on Youtube, I downloaded MSI Afterburner and Kombuster and followed the steps on the guide. but as I went higher the clocks (core clock & memory clock), I got a blue stripped screen while playing some games such as NFS The Run and BF3, I just lowered the clocks with no choice. I can surely tell that it was not a temperature issue because I had monitored the gpu temperature as long as I was running on the gpu, the temperature only maintained at 65c - 70c.
So I did searching on google and some of the forums mentioned that the insufficient voltage is one of the factor causing the blue screen.

My current core clock is 820MHz (overclocked), memory clock is 1140Mhz (overclocked), 100% fan speed, core voltage 1150mV (stock)

I would like to ask, what is core voltage, and how to determine what is the correct voltage that is enough to handle my memory clock and core clock?? Thanks alot =)

 

[Eclipse95]

It is voltage that powers the PGU. First find on the internet what is the maximum operating voltage of your GPU and memory. Than, increase the voltage by the smallest step untill GPU becomes stable. But do not go over the max operating voltage...

Thanks for the reply, I slowly increased the voltage and finally got rid of the problem! =)
But I am still wonder that is there a need to take care of my PSU on supplying the amount of voltage I set, or I just need to take care of my GPU on higher voltages without any concern on the PSU?

 

[Eclipse95]

No.

Ok, thanks alot! =)