Questions about Gigabyte GeForce GTX 970 G1 Gaming

I advise you to take a power supply in the 700W range which must have at least an 80 PLUS Gold certification for a better performance :) and if you want to make your life easier in the assembly take a modular power supply.

For the money, I would definitely rather get a GTX 1080 (like this one: https://www.digitec.ch/de/s1/product/asus-gtx-1080-strix-a8g-gaming-8gb-high-end-grafikkarte-5881304)....

Yes, the mainboard is compatible with this graphics card. The card is relatively long, so make sure that there is enough space at the level of the PCI Express connection. Power supply unit at least 650 watts, one 6-pin plus one 8-pin. I am very satisfied with the graphics card.

The link points to nothing. Usually there is an adapter with the graphics cards so that you can use older power supplies without suitable PCI-E power connections. The be quiet! Straight Power 10 CM (600W) power supply (if it is the correct one) has 4* 6+2-pin PCI Express connections. I.e. everything should fit

There is minimal impact on game performance if you move the graphics card from a PCIe 3.0 x16 to a PCIe 2.0 x16. There will be an impact if you move to less lanes (for example x8 or x4) http://www.hardwaresecrets.com/pci-express-3-0-vs-2-0-gaming-performance-gain/4/