4870 installation

First of all, hello everyone, this is my 1st post!
I considermyself an "average" guy when it comes to computers, but have always been affraid to take the "next" step and doing installations, tweakins on my own. I have always had people with more knowledge help me build my PCs. With those people gone, I guess this is the time for me to learn so here I go.

I got a RADEON 4870 HD card.

The card has two 6pin (i think) connectors (black) and it comes with 2 cables that go from 6pin to tow "drive connections" In other words. from 2 connectors i end up with 4 (four) drive connections (the white tones that we all know)

My question is...... do i need to connect all four of them to power? Just one of each?
I really need some help, because I was not careful to see how it was connected, and when i had to migrate to a new case... I disconnected everything. I first connected one of each.. and when i launched a game... after while my compuer reset itself.... so i know something is not right.

The manual both physical and online only show a similar card with just ONE 6pin (black) PCIe (i belive that is what it is called) connector to power the card... mine has 2 6pin (PCIe)

Also.. what is the "suggested" FAN SPEED - Temperature you guys recommend?

I would like some help and thank you all in advance!!!

Thanks for your reply!!!

I have a couple of questions!!

What do you mean by "That is hwy there are two 4 pin connectors"?
What is the optimal temperature i should get this card to?
What happens if i dont connect all 4 connectors of my card