whats a good psu for the gtx 260?

Look into Corsair or a BFG would be my 2 cents on the matter.

Corsair 650TX (good price at www.buy.com).
Silencer 610W (but I still prefer the Corsair because it has more PCI-E connectors and 2 more amps).

There is no formula. It depends on how the PSU is made. Also, some manufacturers (like Corsair and PC Power & Cooling) are more honest than others and display sustained output at high temps, not peak output at room temps. It can make a big difference.

The simplest approach is to buy a PSU with a single rail (like those two above) and then you know exactly what you get.

Some people have tried to put together a list of "combined amps on the 12V rails" for lots of PSUs. It's here:
http://forums.slickdeals.net/showt [...] 0&t=554094

BFG PSUs are not really that great from what I've read. Their video cards are excellent (yay, my BFG video card still rocks). Corsair, PC Power & Cooling, Seasonic, Enermax tend to get the best reviews.

+1 for Corsair and PC Power & Cooling (the Silencer), they make great PSUs and you can trust the wattage and ampere specifications.

Some of the lower-quality PSU manufacturers only say what the peak output is at room temperature and once you go past that point it starts to degrade again. And really, what PSU runs at room temperature when it's parked inside a case with other hot components? Unless it draws air through an external source, like in bottom-mounted cases.

Yeah, the rails aren't simply additive, except perhaps on some of the Antec PSUs (or it's close). That's one reason I stopped buying Mushkin; didn't like 20A + 20A with a 28A max. That's just too much loss.

750w is more then enough for 2 gtx260 sli. im running 2 gtx260 oc with a quad oc 3.2ghz with a 500w.
=]

thanks. yes im aware im pushing my psu to the max. my total power draw currently is around 420-430w, so a little space is left. im planning to add just one more thing a dedicate physic card got a cheap 9600gso. 9600gso draws around 60w. so taking that into calculation im going to be hitting apx 500w. my psu is 7 months old hopefully it didnt degrade to much. ( i do not recommend anyone attempting what im doing) stupid idea? yes but i have great warranty so just in case something goes wrong im covered.

currently im tweaking mobo voltage so i can save up as much power as possible while remaining stable. ill post back if i get everything to run. should be getting the card tonight.

good bro im happy for you, hopefully when i get my psu, everything will work fine for me too, oohh guess what, the other psu i had running with my rig its half dead, i test it, and it wouldnt even stay on, and i just broke the freaking plastic from pci-e x16 2.0 from my mobo, ima try to fix it with crazy glue, lol see if that fix it

Drivers always have issues. Still, these days they are in pretty good shape, much better than last year for example. No worries there.

The GTX 260 will do better than the 9800GTX in CoD4.

In FSX the video card matters less than in other games. What you really need for FSX is a nice OCd quad CPU.