At full load the GX2 is going to be using 18.1 amps of the total 30 amps that the PSU can provide on the +12 volt rail. If you have energy efficient CPU 95watts or lower 1 HDD 1 optical drive and not a lot of other extra components it might run without instability issues.
this one is my psu if u really cheak it out 9800gx2 will use 6 pin pci and 2x peripheral
it means that i will have 2 left unused (it has 5 1 is uesd by dvd) i can connect 9800gx2 and 8800gt for sure
the website of 9800gx2 says that u will need minimum 360 watt psu
i think i will be able to run both 8800gt and 9800gx2
i m very new and noob to this stuff please help i already made a wrong decision by picking up xfx 750i