A PC enthusiast reports successfully shunt modding his Nvidia GeForce RTX 2070 Mobile GPU for a ~15% performance uplift. An uplift of this scale would bring the RTX 2070 Mobile roughly to performance parity with its desktop counterpart. PC Games Hardware forum member HerrBolsch says he pushed the mobile GPU through its power-limited ceiling of 115W, all the way to 175W (h/t PCGH.de News, machine translated). The electrical tinkering was part of a larger conversion project to re-house and water-cool a Zotac Mini PC.
Areas needing resistor changes highlighted in red (Image credit: HerrBolsch)
GPU overclockers find shunt mods hard to resist
Shunt mods are a relatively common PCIe graphics card hardware modification. In brief, the modder will swap out a shunt resistor on the graphics card PCB for one with a lower resistance value. This change allows more current to get to the GPU without fiddling with the vBIOS. However, the procedure and the results of the resistor change can easily cause damage to your precious GPU hardware.
Getting more power to the GPU can make a significant difference to its performance, especially if you see system tools reporting that your graphics performance is typically power-limited. With a re-housed mini PC and water-cooling plans, it is easy to understand why HerrBolsch was attracted to the idea of implementing a GPU shunt mod here. According to the sources, this particular mod required several resistor changes – five changed in various areas of the PCB, by our count.
To verify the hardware surgery had been successful, HerrBolsch checked a physical Watt meter, as with this kind of mod, software tools like HWInfo and GPU-Z will still report the pre-mod values.
Next, the modder sought to confirm that thermals would remain under control, despite the extra wattage, and that there was a worthwhile performance dividend. HerrBolsch shared some thermal camera images, which suggest there is nothing to worry about in the aftermath of the shunt mod, with top component temperatures around 80 °C under load.
Mark Tyson is a news editor at Tom's Hardware. He enjoys covering the full breadth of PC tech; from business and semiconductor design to products approaching the edge of reason.
