best corsair power supply (CX,CS,RM)

None. What country are you in? There are far better options to be had.

Corsair does not make power supplies. They rebrand power supplies and sell them. For instance, the best corsair (AXi series) are made by Seasonic.
 

Im in Pakistan right now and im very confused . Which power supply should i buy? Thanks for instant reply

 
PCPartPicker part list / Price breakdown by merchant

Power Supply: Corsair RM 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($92.98 @ Newegg)
Total: $92.98
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-01-07 17:36 EST-0500


Another great 550w made by SEASONIC.

PCPartPicker part list / Price breakdown by merchant

Power Supply: XFX XTR 550W 80+ Gold Certified Fully-Modular ATX Power Supply ($76.18 @ Newegg)
Total: $76.18
Prices include shipping, taxes, and discounts when available
Generated by PCPartPicker 2015-01-07 17:37 EST-0500
 

Thanks for reply
My problem right now is that im so confused because there are many power supply companies. ( im new)
Recommend me some power supplies which you thick should be best for me. ( sorry for bad english)

 
the only gold rated power supplies available in pakistan are CS-M and RM while AX is platinum rated.. but since you only need to run a hd 7770 you dont need a high watt psu.. a bronze rated 500 to 600w psu would be fine depending on what fits your budget..

i dont think xfx 550 is available here, i wonder why you'd select it as the best solution..
 
The ones you listed are all good power supplies. The RM is the best of the group.

Don't worry about the naysayers. We are a bunch of hardware snobs here. We split hairs for sometimes silly reasons. We can't help ourselves. You will be happy no matter which direction you go. And corsair has great customer service.

All that said, the XFX TS is a GREAT unit at a great price. Too bad you couldn't get it there