Gpuz may not show you accurate readings. Because driver support and bios may send wrong data but close to real. Only way to be sure is you need special gear which not necessary for this kind of job. As long as pcie not drawing more than 75w it means just fine.
The limits for the voltage consumption by the video card are set in the BIOS.
The video card will not be able to consume more than 75 watts via PCIe
The less the video card consumes electricity from the motherboard, the less load on the motherboard. Possibly lower power consumption will increase the lifespan of the motherboard.