Fear no more ! With this guide, i ensure no software restraints of your Overclocking for graphics cards !
Ok. After facing some irritance from the testing and limits of Rivatuner, I fooled around with Riva's Poweruser section in a bid to make graphics card overclocking less of a hassle. I don't know whether this has been posted or not, but i'll just post it. =D
With this, you have a limit-free clock frequency for setting, and no need to test for settings before you can apply them! Doesn't it sound great ?
Note: This might cause your graphics card to have artifacts. By reading this, you take full responsibility to any damages caused to your graphics card.
Note: I'm also using a nVidia Graphics card now, so for Ati users you can try but i won't guarantee success.
First things first. I hope you have overclocked your max speeds on your graphics card on a 'locked' Rivatuner. This will make sure it doesn't crash and gives us a rough benchmark to set the speeds.
Instructions
Next, open up Rivatuner.

Go to the poweruser tab and ignore any warnings if any.

Search for -> Rivatuner 2.08 \ OVERCLOCKING \ GLOBAL.

Follow and set specified settings.

Search for -> Rivatuner 2.0 RC 15.8 \ NVIDIA \ OVERCLOCKING.
Set specified settings.

Walah ! There you have it ! Effortless overclocking !
I can't show screenies of the disabled clock test but i can show the difference in maxclock limit.
Before

After

If still not enough, change those values to above 100. Then from now, add 1-3Mhz on the core to test and memory. Once you can clearly detect artifacts, please revert the settings or risk damaging your card permernantly.
















Linear Mode

35 OCZ Fans!