Unlocking the Nvidia Power Limit (all cards!)

SMD Current Measurement Basics

The power consumption measurement is a pure hardware solution on all latest Nvidia cards. So even if you manage to adjust or increase the Power Limit in the bios you might still be limited. The only proper solution is a hard-mod which is quite easy though.

Let’s take a look at basic electronics first:

basics1

In the picture above you can see a simple electronic circuit with a supply voltage of 12 Volt and two resistors with 100 and 200 Ohm. Following Kirchhoff’s voltage law, all voltages added up equal zero (U1=U2+U3). Kirchhoff’s current law says that the current is constant in a serial circuit (I=const).

Using Ohm’s law (R=U/I) you can calculate the total current of the circuit and the voltages of each part (R1 & R2).

Graphics cards usually have a quite high current flow between 10 A to 25 A. It’s not possible to directly measure the current flow using SMD components. However you can use a simple trick to measure the current flow my adding a SMD resistor with a very low value.

basics2

 

A very small resistor in front of the GPU will lead to a small voltage drop. These resistors are called shunt resistor.

In this example 0.00006 Volt which can be measured without any problems. By using Ohm’s law again you can simply calculate the resulting power consumption using P=U*I. The measured voltage is proportional to the current flow.

To change the result you have to change the resistance of the shunt. E.g. lowering the resistance by 50 % to 0.0005 Ohm will double the power target because it will only read 50% of the real power because the measurement still thinks the resistor has the same value of 0.001 Ohm.

The solution: lower the resistance

The easiest way would be to solder across the whole resistor which I would recommend to extreme overclockers. However, if you just want to overclock on air or water and want to keep your warranty there is an easier solution.

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