Well-known Korean cooling company Zalman is also known as a manufacturer of high-quality power supply units (PSU) and computer cases. Now, the company has just launched a new PSU line with 80 Plus Gold certification. The new PSUs from Zalman are called GoldRock XG and the efficiency ranges between a minimum of 88% and a maximum of 92%. An efficient power supply unit will reduce the computer specific power bill but it will also reduce the air conditioning power bill in summer. The less efficient a power supply unit is, the more heat it dissipates into the room. While in the winter this extra heat might be welcomed, in the summer this would make the room even hotter than it already is. When your power supply unit is less efficient, it consumes more energy and dissipates the same amount of energy into heat. Many readers may not know, but if a PSU dissipates more energy into the room, let’s say for example 100 watts more, in ten hours your PC will consume an extra 1 kilowatt that you will have to pay for at the end of the month. That 1 kilowatt worth of heat is probably desired during winter, but in the summer your air conditioning unit will consume roughly 1,1 kilowatts to take that heat out of the room. Therefore, a less efficient PSU is twice more costly in the summer than it is in the winter. Zalman’s GoldRock XG power supply series reportedly feature high-quality solid capacitors and Japan-made electrolytic capacitors that are rated to function in high temperatures reaching a high 105 degrees Celsius. The new PSUs have a single 12V rail and each of them can deliver over 90% of the output to the 12V line. The first unit is called ZM550-XG and is able to deliver 540 watts to the 12V line. The second is Zalman’s ZM650-XG, and it can output up to 648 watts to its 12V line, while the ZM750-XG model is able to deliver 744 watts on the single 12V rail. Pricing is set at $134 (€108) for the ZM550-XG, $145 (€117) for the ZM650-XG and $158 (€128) for the ZM750-XG.