8pin powercable on P5BDLX, necessary?

This question has probably been asked numerous times before, but I'ma go ahead and ask again.

I'm building a system for "friend" of mine, composed of the following components:
Asus P5B DLX Wifi
Intel E6400
PowerColor X1950XTX
Corsair Twin2X P6400 C5
2x Samsung Spinpoint 250GB
NEC DVD-burner

I have found a case, the Antec TX1050B-EC, which also comes with a 500W psu (which I'm also wondering is any good). I don't know whether this comes with a 8pin power connector or not, but if it didn't, would that matter?

it will use either 4pin or 8 pin

on the Antec TX1050B-EC need to know what the 12V rails are like...

Jah... What I'm most curious about is whether 8PIN is neccessary or not. Will it bring any performance gains?

Bump.

Hasn't anyone got a somewhat clear answer to this?

kinda curious about this myself.

using 1 4pin at the mo

It is not necessary.

Mine came with the second 4 pins covered with a cap & no instructions on that, so i left it alone.

its not necessary but the 8-pin add's extra needed rails to the mobo for a stable vcore etc etc.

if you have a psu with an 8-pin use it if not,, then you dont have a choice.