We use Nvidia PCAT to measure power draw of the graphics card only, with readings from both the PCIe slot and the PCIe power cables combined into a single figure. We use Resident Evil Village (4K) for this testing.
As for power draw, it’s important to note that the iChill X3 has not increased the power limit of the card, so it’s still rated for 320W like the Founders Edition. In practice, we saw it draw 314W in Resident Evil Village at 4K, so very similar to the Gigabyte Gaming OC