VR-Zone posted up an interesting tutorial on how to volt mod a 9800GX2. As with any modification to a GPU, its warranty will be VOID. I wouldn't dare try this to my own precious card. The fact of Stepping-Up to the 9900GX2 is far much more important than a voltage mod at this point.
http://www.vr-zone.com/articles/Preliminary_Voltage_Modifications:_NVIDIA_9800GX2_VGPU_Modifications/5651-2.htmlTutorial:The NVIDIA 9800GX2 has just hit the shelves and at VR-Zone, we work out the Voltage Modifications before anything else. Here's a little preliminary modifications for those who are flying the soldering iron, and SLIcing up some double patties.