Factory OC'ed cards and overclocking in driver

[CakeMonster]

I have never owned a factory overclocked card, how do they work with regards to turbo, overclocking and drivers?

For example my 7970 vanilla has max limits (those are very low) in AMD Overdrive in the CCC. If I bought a card which was factory OC'ed to one of those max limits, would I then have additional headroom in the driver OC panel?

Do these factor OC'ed cards have their own Turbo setting in their BIOS specifying how the drivers will treat it compared to standard clocked cards? I mean, say that a model is 1000mhz and turbo is 1050mhz. If the manufacturer clocks it at 1100mhz, will drivers and/or BIOS (or whatever is in charge of dynamically adjusting turbo) automaticially use 1150mhz for turbo? Is it +XX mhz fixed or is one specific total mhz speed programmed somewhere?

The most important reason that I'm asking is that I probably am not going to bother with using extra software to OC and if I'm left with less headroom over a vanilla card then there is less reason for me to buy a factory OC'ed card.

 

[blackened23]

I haven't used the 7970 in over a year but from what I remember, the limits in CCC are dependent on registry entries? Or something along those lines. You can use Afterburner to go further than the max even on reference cards, but you have to modify the .cfg files.

 

[CakeMonster]

Yep, I used Afterburner for a while when the card was new and it was a major PITA with new versions for new drivers and having to make it load on startup etc. So I'm thinking that the next time I upgrade my card I'll probably go with a custom factory oc'ed card (also with custom cooling because I'm sick of ref design noise).

So it's more of a general question, not necessarily about 7970, but about all factory OC'ed NVidia and AMD models these days, especially new newer cards.