When it comes to power consumption, the KFA2 GeForce RTX 4090 SG is no exception compared to other GeForce RTX 4090 models. At 450 watts, the standard power limit is as high as other RTX 4090 models. of optional power, on the other hand, there are differences between the different models. With a plus of 13 percent, you can increase the power limit of the KFA2 GeForce RTX 4090 SG to about 510 watts. Nvidia’s Founders Edition even allows up to 600 watts and the Palit GeForce RTX 4090 GameRock OC only 500 watts. In practice, however, this is of secondary importance, since the power limit of 450 watts is rarely reached. Just over 370 watts are consumed in the FurMark stress test. The GPU temperature is 65 °C and the fans spin at only 1300 revolutions per minute. The graphics card is quietly audible at 39 dB(A).
The KFA2 GeForce RTX 4090 SG relies on a massive heatsink with three large 102-millimeter axial fans. Another 102mm fan can be installed at the rear as an option. Here, however, attention must be paid to the compatibility with the motherboard used. In our case, the additional fan could not be installed because the RAM banks of the Gigabyte X670E Aorus Master prevented it.
If we compare the power consumption of the entire test system, it is around 546 watts when gaming. This is only slightly more than the Nvidia GeForce RTX 3090 Founders Edition. However, we do see a significant increase in performance, which means that the GeForce RTX 4090 takes a big step forward in terms of performance per watt. However, we also recorded load peaks of up to 700 watts for our test system. KFA2 specifies a power supply output of at least 850 watts for the GeForce RTX 4090 SG. Some other manufacturers, on the other hand, use at least 1000 watts, which we think is too high.
On the subject of the 12VHPWR connection, we would like to point out at this point that you need to make sure that the plug is correctly and fully inserted into the socket. There are no issues with all the RTX 4090 models we’ve tested so far and still own.