If you are sure it says you only need one, and you only have one, put it in. It will start or not, but you wont damage it by trying. Just dont leave it on if it doesnt start, no point in further risks.
where did you read this? it needs 2 power connectors to provide the correct volts. if you only use 1 the card will likely not boot.
if you only have 1 pci-e 6 pin then you can always use a 6-4pin molex adapter to get the extra power needed, assuming your psu has enough to start with.
so no you will need 2 6 pin connectors if you dont already have them, the the card ships with the required adapters.
The card came with two six pin power come torso that plug not the guy into a molex connector.
On the bag it came in it says connector options: 1x4 pin 1x6 pin 1x8 pin 2x4 pin 2x6 pin 2x8 pin 1x8 pin+ 1x6 pin. I'm not too wavy with all the power stuff
AMD recommends a minimum of a 500 Watt psu, the power supply should also have a minimum combined +12 Volt continuous current rating of 30 Amps or greater and have at least two 6-pin PCI Express power connectors.
You are mis understanding. It doesnt mean options for the card, it is just a list of contents.You need to fill all the sockets on the card or it will refuse to run.