Real needed power for GPUs

[Shevek]

I'm about to buy a 5770 (consumption ~108 W), but don't want to purchase a new PSU. Mine actually gives 350 W and works fine with 5570 (~43 W) overcloacked and "overhashed" to ~80 MH/s. I want new 5770 to substitute old 5570; so they won't be rigged together.

But all sellers advice me to upgrade my PSU up to 600 W if I want no risk of burning out.

So the question stands: do I really need to upgrade PSU? Or is it an oversized advice?

[xurious]

Which CPU are you running? How many hard drives, fans, etc.

Use this for a much more accurate power consumption configuration.
http://extreme.outervision.com/psucalculatorlite.jsp

[quattro]

It depends on the brand of power supply and efficiency as well as the rest of the components in the rig.  I've run two 5770s off an Antec Earthwatts 80 plus certified 430w.

[Shevek]

Use this for a much more accurate power consumption configuration.
http://extreme.outervision.com/psucalculatorlite.jsp

Thanks for the link!

I have no precise data about my equipment now (I don't remember about 7200 rpm or 5400 rpm...) but with approx. data it yields 249 W for actual card and 299 W for 5770. So it's ok, with no big margin.

Anyway, when card is intensively used, the rest of hardware quiets a lot.