Is 250watts power enough for rest of PC?

[SSK5499]

Hi Guys.I was thinking to crossfire the AMD Radeon R9 280x's but that will need 500watts power.If i install a 750watts PSU would 250 watts enough to supply power to the rest of the computer i.e 12Gb DDR2 , 1Tb HDD ,1 Tb Seagate expansion,processor(Quad Core Q9550 2.83 GHz),DVD ROM?
Would it be enough or i crossfire the R9 280's instead for 400watts Power requirement.
Help me Plzzzzzzz
Thanking in Advance 😉

 

[RektSkrubs]

750watts will be well enough. My setup that I use, even though it needs a pci-e 8x and 6x connected to the card, it only uses about 308w...

http://pcpartpicker.com/user/RektSkrubs/saved/#view=2DYzK8

 

[Xorak]

I was able to run two 290x's and an i5 system off a Seasonic 750w, with the whole thing over clocked a bit. That said, I would (and did) get a more powerful unit to ensure some headroom and to keep it in a more efficient range. Above all, make sure to buy a quality, preferably single rail unit.

My personal experience with crossfire was negative. Most of my games didn't support it. Support for new games is especially hit or miss. In some cases it made the performance much worse. MWO for example. So, see my above advice, but I also strongly suggest going for a single more powerful card. I took the other 290x back out and am happier. I have the powercolor pcs+ 290x which you can snag now on Newegg for $300, which is exactly what I think you should do before they're gone. Unless you want to wait and see what happens with lower Fury variants like the nano. It's supposed to be faster than a 290x, but I don't know about price points or release dates.

 

[bootcher]

A PSU doesn't exactly work as you described, as you can divide it into two parts for 500 watt for the videocard(s) and 250 watt for the rest.
To crossfire 2 R9 280x you would need a good PSU in about 700 watts range or higher. It depends on what brand you are choosing. I would recommend a good rated brand such as Seasonic, XFX, EVGA, Rosewill Capstone, Antec, etc. You can look up some of the better PSU brands here yourself:
http://www.tomshardware.co.uk/forum/id-2547993/psu-tier-list.html