We measure system-wide power draw from the wall while the card is sat idling at the Windows 10 desktop for 30 minutes. A reading under load comes from running the 3DMark Fire Strike Ultra stress test 20 times.
Considering it has a total of 3x 8-pin PCIe power connectors, a huge 16+3 power delivery implementation, and runs at over 1920MHz – it is perhaps not a surprise to see this Lightning Z draw a lot of power. In fact, it even draws more than Vega 64, while Nvidia's Founders Edition RTX 2080 Ti pulls about 80W less.
Like I said on the previous page, however, this card is all about performance – not, in this case, power efficiency. This obviously isn't the card to get if you need something cheap and efficient to use with a 500W PSU. If you're an enthusiast overclocker, however, I can't imagine the power draw would bother you in the slightest.