Voiding your warranty
In such an extreme environment, there isn't any questioning potentially dangerous enhancements like voltage modding—it's a given part of the competition.

Team USA-1 got out the hot glue gun and soldering equipment right away

Graphics card makers keep power regulation on a tight leash, but if you can create a short in the right place on the circuit board and insert a relatively low impedance resistor in the new circuit path, you can safely deliver higher voltages to the GPU, allowing for higher clock speeds.

Basic printouts were actually quite rare

Each team went about voltage modding in similar ways; a soldering iron, some variable resistors and wires, and steady hands were pretty much all that was needed. More interesting was how the participants kept reference materials detailing the modifications.

An Acer Aspire One was used by one team...

All the teams used the same hack. Once one person in the community finds the proper points to short and valid loads to introduce to the new circuit, a high-resolution image of the surgery is all that is needed by anyone who wants to duplicate the mod.

A few used their smartphones

Part of the process involved checking the properties of the circuit before, during, and after the mod to ensure nothing went wrong. For this task everyone had their trusty digital multimeters ready, with some teams leaving probes permanently attached to the key points to monitor levels while everything was running.

Everyone had at least one multimeter handy to check their work

What really stood out about the modding was the fact that this was all taking place under the pressure of an extreme time crunch. Any time lost to a soldering snafu could mean the forfeit of a score in an event if the system could not be brought up to speed in time. It should come as no surprise, then, that the more experienced modders had a real advantage. They were practically professionals at working with the minute details of a voltage mod.

The points they had to solder were absolutely tiny

Some teams also employed a "droop" motherboard voltage hack.

Some teams went so far as to modify the motherboard, too

This warranty-voiding procedure let teams more finely control the stability of the voltage provided to the CPU. Some teams deemed this mod "only marginally beneficial," but others declared it "essential" at the extreme clock speeds desired.

One of the soldering points on the mobo was on the front, directly to the right of the thumb

The motherboard mod took roughly as much skill as the graphics card one, but was a little trickier due to the fact that the solder points were on opposite sides of the circuit board.

The other point was on the back

My favorite part about these mods was the attention to detail some people were able to put into them in the short amount of time available. Cables were routed neatly to switches that could turn the mods on and off as demanded by some of the teams.

A variable resistor, conveniently placed

To ensure stability, other teams ran variable resistors that could be tuned once the machine was on.

Both American teams paid a great deal of attention to their mods, including team 2,
whose setup is pictured here

A couple teams were even watching current levels through ammeters, allowing them to cut power if too much current flow threatened to damage system components.