NVIDIA 7950GX2 Voltage Mod Guide
The 7950GX2 are built for high definition gaming, so squeezing the extra clocks out of them will help smoothen that 2560×1600 gaming experience. VR-Zone shows you a few tips…
**Take Note that Voltage Modding will void the warranty of your cards so do it at your own risk!!**
Voltage modding will increase the heat output so be sure to cool the cards well, which is especially challenging within the confined space of the primary board.
First, let’s take a look at the GPU Core voltage spots. Even though the primary and secondary boards on a single 7950GX2 are not exactly identical, the mod and voltage read points are exactly the same. You will need to dismantle the twin PCB card to reach the inner board. In any case you should be switching to some better cooling solution when you go voltage modding so you’d have to seperate the 2 cards. However, do not test run the 2 PCB half seperately!
Take a look at the back of the board and you should find the Intersil ISL6568 core voltage regulator.
The GPU Core voltage measure point is indicated above. The default voltage when running 3D applications is 1.3v. To increase VGPU to 1.5v, connect the 2 points marked above in Step 2, using conductive ink/pen. For 1.55v, after doing Step 2, connect the 2 other points marked in the same diagram and you get 1.55v.
To get even more core voltage, you can ignore the mods just listed. You will need to unsolder a small SMD resistor and replace it with a 50K ohms resistor by soldering the resistor in its place.
Replacing the resistor will straightaway give you 1.6v VGPU without any point connecting using conductive ink. To get 1.65v, after replacement of the resistor, connect the 2 points marked in the diagram above using conductive ink/pen. That will give you 1.65v but be sure to provide good cooling!!
Let’s take a look at the voltage measurement points on the front of the card. As it is, you will probably be accessing measurement spots on the first half of the 7950GX2 from the back of the card, and the measurement spots on the second half of the 7950GX2 from the front of the card:
VGPU and Memory Voltage measurement spots on the front of the card is as marked above.
The VGPU measurement spot from the back of the card is already shown at the beginning of this article, so now we take a look at the Memory voltage measurement spot at the back of the card:
The default Memory voltage for the GDDR3 Memory is 1.92v. To increase the Memory Voltage, you can pencil the resistor marked below:
Original resistance of resistor is 585ohms. Memory voltage will go up in +0.05v increment for every 20ohms reduced, so dropping it to 565ohms will increase voltage to 1.97v, for example. Alternatively, instead of pencil, you can just solder a 10K ohms variable resistor across this resistor, set at maximum 10k ohms. Tune down resistance to increase voltage.
Well, there you have it! GPU voltage and Memory voltage mods! As the 2 halfs of the single 7950GX2 shares the same clock speeds, so if you voltage modify one half be sure to do the same to the second half. If not, you’d still be dragged down by the unmodded card. The 7950GX2 should be reference design for quite a while so this mod guide should be pretty universal. Lastly, be reminded that these mods are at your own risk, and that warranty is voided when undertaking them. And cool them well… you should enjoy higher clocks if you do things right!