6870 and PSU

Probably but with lots of noise and eventual component damage.
Don't buy a CoolerMaster GX psu they suck!
http://www.hardwaresecrets.com/article/Cooler-Master-GX...
Seriously dude how many times do you need to make a thread?
Good units.
CORSAIR Enthusiast Series TX650 V2 650W
http://www.newegg.com/Product/Product.aspx?Item=N82E168...
http://www.newegg.com/Product/Productcompare.aspx?Submi...

what about this 1 CORSAIR 600 WATTS (CMPSU-600GUK) NON-MODULAR (12V / 48A) ?

the XFX 1 is not available in my country

If you cannot get one from Corsair, try Antec.. The Antec TP 750 will suit your needs precisely.. Its an excellent unit too..

I wouldn't use anything under 650W.
Any high quality 650W would be fine because they actually produce much more power then labelled.
http://www.guru3d.com/article/radeon-hd-6850-6870-cross...

ANTEC EA650 650WATTS CONTINUOUS POWER ?

i am gonna buy this 1 http://www.newegg.com/Product/Product.aspx?Item=N82E168...

I use a corsair 850 in my 6870 cross fire setup and it works perfect with my cpu cooler, my huge overclock and my multi ssd and hard drives. Do not go cheap on the psu there a lot of technology here at stake! http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Your cutting it close with that power supply!

Go ahead if it's anything like the 750W version it's a complete pile of junk!
http://www.hardwaresecrets.com/article/Thermaltake-TR2-...
How many times do you need to be recommended a Corsair TX or Antec EA or TP unit.

Look. If you want to buy something that's guaranteed not to blow out and annihilate your system, then buy a Corsair, Antec, XFX, or one of OCZ's better units. If you don't want to take recommendations, then it's not our problem when your PSU starts to fail.

Corsair 750w:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Antec Earthwatts 750w:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...

OCZ ModXStream Pro 700w:
http://www.newegg.com/Product/Product.aspx?Item=N82E168...