Further update. The NVStrap method isn't perfect. One way or the other RivaTuner has to be run before the pipes become unlocked. But, you can't see that they're unlocked without running RivaTuner. Most users might not've noticed. I tested the theory through benchies.
The real trick comes with pulling an image of the VGA BIOS and using one of the patch scripts to mod the image into unlocking the pipes before the registry has a chance to shut them down.
You need to understand how the masking of the pipes works. Some people like to think that Nvidia actually shut down the pipes cold back at the fab plant, but this is incorrect. The shutting down of the pipes is actually done by the card the core sits on, not the core itself. A particular brand could use perfectly good (as in no defects) NV40s on normal 6800 cards without a problem. The company would just design the board to lock out those pipes so Nvidia will allow them to sell it.
Now, this is why I recommend using XFX for this mod. I have yet to see an XFX 6800 that has damaged pipes, not simply locked ones. With other companies, like eVGA, Gainward, etc, they're a little more inconsistent in that some of their chips are the ones that Nvidia tested and saw had bad pipes. These will artifact or even cause your machine to lock-up if you try to enable them.
My personal belief is that XFX is just being efficient and throwing the slower of the perfectly good "GT" cores onto 6800 boards that are designed to lock some of the pipes. My card is a perfect example in that even with the locked pipes active, it will still do 381mhz on the core.
On to how the boards lock the pipes. There is a resistor mask location for every set of 4 pixel pipes (Nvidia grouped them in sets of 4) and every single vertex pipe in the core. Now, if a resistor is soldered to that location, here is what happens. On boot, only the first 4 pixel pipes are running and no vertex pipes. This simply shows loading screens and the BIOS interface. As Windows loads, the registry signals these mask locations. Where it detects a resistor, it now knows the manufacturer wants those pipes locked and then enables whatever is left for regular operation. All this happens during that Starting Up screen. So, a simple registry change will enable all the pipes, right? Sorry, but no.
These registry settings aren't saved on the HDD. They stay in the system memory or swap file. We need to have some way of beating the registry to the punch and keep those pipes open. What is going before the registry? Well, you motherboard's BIOS and... you guessed it. The VGA BIOS.
Unwinder included in the
RC15.3 edition of RivaTuner a patch script which will mod an NV40 BIOS image to keep the pipes unlocked, bypassing that "hardware" mask. Then, all you need to do is use
NVFlash to flash the new BIOS to your card and your set.
Very Important!!! Properly test your pipes with the NVStrap driver before doing this. If those pipes are bad, then you'll be in a world of hurt when your VGA BIOS forces them to work. In some cases, you might never get the thing to load to Windows anymore.
ALWAYS save a copy of your old BIOS as well. Anyone not familiar with flashing a VGA BIOS should read the directions and disclaimers associated with it before attempting. No bull, it can be risky. If nothing else, have a PCI video card handy in case the flash goes bad and you need to reflash the AGP/PCIe card.
Again, this is why I recommend the XFX since they're using a GREAT batch of NV40 chips. This guarantee won't hold for more than a few months as cards with a different batch of NV40s that XFX bought hit market. We'll have to wait and see.
Assuming all is well, your card will automatically configure itself for 16x1 6VP on boot. Even if you move it to another PC. Well, I wish you luck and any questions can be directed to me here through private messages. I will gladly do what I can.
Personally, I've only played with this option. Tonight, I'm going to go all the way and flash it with the modded BIOS. Will post back with a final update on the results.
Edit: Mental note - update signature image.
Login
Register
FAQ
Search
