The G70 should equal current SLI performance or beat it with just one card.
No it doesn't, I just posted info about this the other day...the G70 will get approx 8xxxin 3dmark05 and SLI'd 6800GT's get around 10k....so it's just under it, but still damn good, and with good cooling I'm sure it'll OC nicely too.
500 watt PSU, dunno what that means in terms of moltex(?) connectors.
The moltex connectors are the ones that connect to perpherials from the PSU, right?
It's 'Molex' not moltex.....and I see you got the guy below you typing that too....
500w means exactly what it says.....500w of power....it has different voltage lines, primarily the +12v, +5v and +3.3v that all have certain rated amperages.
If your +12v line is 20a then you multiply the two 12x20 = 240w.....each rail has a specific amperage, so when the amps is multiplied by the volts you get the wattage, add up all the wattage and you get bam "500w PSU"
mind you there are also negative voltage rails.
As been said, the 6800GT is a powerful card....ridiculously powerful GPU which I think most people don't understand that todays GPU's are far more complex than a CPU....has millions more transistors and is just overall architecturally and in terms of processing more complex....it can't get enough power simply from the slot.
Dual cards isn't worth it IMO, plus dual GPUs on 1 card will start to be common, BUT the thing is, by the time you'd be ready to upgrade to a ridiculous card the 6800GT should be really cheap in which case it might not be bad to use two cards, but mind you not every game supports SLI, they have to be coded to use it.