Enough power for r9 280x?

No, that card requires more power than normal, namely two 8 pin connectors and 750w.
http://www.sapphiretech.com/presentation/product/?cid=1&gid=3&sgid=1227&lid=1&pid=2072#

Plus, the CX line is considered as only mediocre quality.
Look for Seasonic, xfx, or antec for starters.