The problem is they are using different time bases for the surge duration. A typical surge duration is 100 microseconds. Some manufacturers use one millisecond. Other manufacturers use one microsecond. The answer is obvious.
Most computers use transformers and capacitors in their power supplies.
These devices, unlike resistors and light bulbs, are very different in their electrical characteristics. Computers do not. To deliver electrical energy to a working device it takes energy in the form of volts and amps. You can have lots of volts and no amps, or vice-versa, and no work is being done. In the U.S., standard electrical systems are rated at 120VAC for small plug-in appliances so the only thing we can vary to get more energy available to an electrical appliance is to raise the ampere rating of the wiring of the power supply feeding the device.