The NVIDIA 512MB 7800 GTX is an awesome performer, with great overclocking
potential. As it is, the cards produce quite an amount of heat so if you do plan
on doing some voltage modding to enhance overclocking, make sure you have aided
cooling. Then, you can head this way…

The NVIDIA 512MB 7800 GTX is an awesome performer, with great overclocking
potential. As it is, the cards produce quite an amount of heat so if you do plan
on doing some voltage modding to enhance overclocking, make sure you have aided
cooling.

Below, you see that voltage mod hot spots:

 

For VDD mod to increase voltage to the 1.1ns Samsung GDDR3 memory
modules, solder a 100K ohms variable resistor to the points marked below. Set
it to the maximum resistance of 100K ohms.

You can measure the VDD voltage from the point marked above. Default voltage
is 2.2v. Tune down the VR slowly to increase voltage.

For VGPU, you can measure it from the point marked below:

Default voltage is 1.25v in 2D and 1.45v in 3D.

 

Solder a 200 ohms variable resistor to the point marked above. Set it to 200
ohms and connect the other leg of the VR to any ground.

Tune down the VR slowly to increase voltage.