Yes, I'm running a Tri-X R9 290 OC off the same PSU with no problems, but if your system has a heavily overclocked AMD CPU or other power hungry parts you might want to move to a 700 Watt unit.
A lot here will tell you the CX series are not good and they're not the best but they are serviceable, their main drawback is they use lower quality parts ( capacitors) that have a shorter life then those found in more expensive units.
Unless you're going to run the system 24/7 as a bitcoin miner I wouldn't worry.