Production (cont’d)/Modding

NVIDIA decided to implement two distinct lines for PCI-E GeForce 6800 cards because it was discovered during production of AGP-based NV40 that yields on 16-pipeline GeForce 6800 GT/Ultra were quite good, so rather than putting a costly 16-pipeline part into a mainstream product like the GeForce 6800, they decided that it was better to go with a distinct manufacturing line for this product that is built from the get-go with only 12 pipes.

It’s because of this that PCI-E GeForce 6800 cards can’t be modded into 16-pipeline cards. Basically, their NV41 graphics core only features 12 pipelines so there’s nothing turned off at the factory. Since AGP-based GeForce 6800 cards are still built on NVIDIA’s 16-pipeline NV40 core, they can still be modified to run with 16 pipelines. (In theory it’s possible that you could potentially get lucky and find a PCI-E GeForce 6800 card that is built on NV45, but the odds of finding one of these cards are incredibly long).

What we’re here today to find out is how fast a GeForce 6800 vanilla modified to run with 16 pipelines can run. Let’s get started.

Modding the card

First, we’ve got to turn on the pixel and vertex pipelines. Since NVIDIA hasn’t physically disabled these pipelines, GeForce 6800 cards can be modded to run with 16 pipes via BIOS modification in software. This is known as software modding or softmodding. Softmodding is preferred by many enthusiasts because it’s easier and safer than hardware-based mods (i.e. you don’t have to grab a soldering iron or any other tools to physically modify the hardware).

Softmodding has the added bonus that if the mod doesn’t work, you usually can revert the hardware you’ve modded back to its original state. In other words, you can easily undo the changes you’ve made, sometimes with just a few mouse clicks. This is important in case your hardware doesn’t work properly after it has been modified (here we should also mention that modding your GeForce 6800 to run with 16 pipes will void your card's warranty, so proceed with care).

Fortunately, there’s a software utility out there that does all the hard work for you: RivaTuner. You can grab the latest version of RivaTuner right here, from Guru3D.

With RivaTuner 15.5 in hand, we set out to unlock the pixel and vertex pipelines in our EVGA e-GeForce 6800 card. First, we’ll unlock the GeForce 6800’s pixel shaders. This is accomplished by turning on the quad that’s been disabled by default at the factory. Once you load up RivaTuner, you’ll be greeted by the Main menu tab:

RivaTuner main menu

From here you’ll want to click on the customize icon in the “target adapter” field, immediately you’ll be greeted by six icons. You’ll want to click the first one “low-level system settings”.

You'll want to click on the first icon

Click on the first icon, it looks like a graphics card

Under the low-level system settings tweaks menu lie two tabs, “AGP” and “NVStrap driver”. In order to manipulate the shaders, click on the NVStrap driver tab.

The Low-level system tweaks settings menu