Is the power control slider on AMD overdrive changing my voltage?

[Vulpes vulpes]

I'm not exactly sure what the slider is doing. I have a 7870 GHz edition I'd like to overclock but I'd rather try an OC on stock voltage first. I'm using this guide on guru http://www.guru3d.com/articles_pages/radeon_hd_7870_overclock_guide,2.html . So does the slider change my voltage? Could someone explain it's function please

 

[Aris1978]

This "power" control option, doesn't tweak the voltage. It just increases the limit of power from the PSU that the GPU can accept. Which means if the card needs to draw more power for a demanding game, it will be possible to do so if you increase the power limit from this setting. This is totally independent from voltage tweak/ overclocking. It helps your gpu perform better though. If you increase the memory and clock frequencies too you can achieve a good overclocking with default voltages.

 

[Vulpes vulpes]

Is it advisable to use the CCC power control slider at 20% while using another GPU OC program if I want to tweak using voltage? Or would it be better to set CCC back to default factory values and voltage OC tweak through the other program. Also, is there a community agreed apun overclocking utility that's used with AMD products opposed to intel or use whatever I find

 

[Vulpes vulpes]

Also, is it safer to use the power slider opposed to voltage tweaks from another program?

 

[Aris1978]

Nope, that's not recommended. For overclocking you will use Catalyst Suite alone, OR use the GPU manufacturer's utility for overclocking but set the Catalyst at default values and disable overdrive totally.

 

[manofchalk]

The Power Limit basically states how much power the card can accept before it starts throttling itself to stay within vertain power consumption limits. If your overclocking im guessing power consumption isnt a huge concern, so max the thing out.
Overclocking also does increase power draw, if you overclock and dont increase the power limit, your card may never hit its overclock frequency as it will be throttled down. Good example of that is a 7970, you can overclock to 1.1Ghz quite easily on stock voltage, but if you don't adjust the power limit it will only ever go as high as ~975Mhz

 

[Vulpes vulpes]

So even though the power slider allows more energy into the card does that mean it's safer than adjusting the voltage with, say, MSI Afterburner. I overclock CPUs through BIOS a lot but this is alien to me so I apologize for the questions.

So what do people feel is safer, just sliding the power control to 20% and OC on overdrive or adjusting the voltage by .005~.010 at a time on afterburner.

 

[manofchalk]

The power limit doesnt affect the voltage, it only allows the card to draw more power. Voltage and Power Limit are separate things.
If your overclocking, you still need additional voltage to keep the card stable.